NewAircraft Fuel Cell Technician (Class C) Tank TigersAircraft Fuel Cell Technician (Class C)Oklahoma City, OKThe Aircraft Fuel Cell Technician (Class C) reports to the Facility Supervisor and/or Facility Manager and performs assigned aircraft fuel tank maintenance in accordance with approved maintenance data, customer requirements and Repair Station procedures. Supporting commercial, military and cargo operators throughout North America and Europe, our highly trained technicians help customers maintain safe, reliable aircraft while minimizing downtime through responsive, high-quality maintenance solutions.
NewField Service Technician (Entry Level) - Tulsa, OK Procter & GambleField Service Technician (Entry Level) - Tulsa, OKTulsa, OK$21.74–$23.26The Senior Field Service Technician (FST) is a field based position working independently to install, troubleshoot, repair, and maintain our chemical dispensing equipment as well as other equipment used in commercial foodservice or laundry operations. Stand, sit, and/or walk for long periods of time, twist, bend at the knees, stoop, kneel, squat, crawl, and reach for purposes of installing and maintaining equipment.
NewField Technician III Sunstate EquipmentField Technician IIIOklahoma City, OKPlus, with benefits like Baby Bonding, My Holiday vacation time, and discounts on everything from movie tickets to cell phone bills, we're constantly evolving our resources to provide our people with tools to make their lives easier! We are working hard to challenge the typical ways of business and develop an environment where our employees feel safe, comfortable, and look forward to coming to work.
Drive Test Technician - Central Region Adex CorporationDrive Test Technician - Central RegionOklahoma City, OKDrive Testing: Operate drive test equipment (e.g., TEMS Pocket, X-CAL, QXDM) in vehicles or on foot to collect RF data across designated routes and clusters. This role supports engineering teams by collecting field data to optimize coverage, capacity, and quality of service across 5G technologies.
Computer Assisted Ordering Technician U.S. Department of DefenseComputer Assisted Ordering TechnicianFort Sill, OK$40,736–$52,957 / yearPriority Placement Program, DoD Military Reserve (MR) and National Guard (NG) Technician Eligible (PPP DoD MRNG):In order to receive this preference, you must choose the Military Reserve and National Guard Technician eligibility, and fill out and submit the Military Reserve and National Guard Technician PPP Self-Certification Checklist and copies of the appropriate documentation. Priority Placement Program, DoD Military Reserve (MR) and National Guard (NG) Technician Eligible (PPP DoD MRNG):In order to receive this preference, you must choose the (PPP DoD MRNG) eligibility, and fill out and submit the Military Reserve and National Guard Technician PPP Self-Certification Checklist and copies of the appropriate documentation.
Door Assembly Technician Trinity Employment SpecialistsDoor Assembly TechnicianTulsa, OKEmployees are expected to participate in daily housekeeping duties, maintain a clean and organized work area, take notes during training, and follow all safety and security policies. This position is responsible for assembling door components, interpreting blueprints, performing final assembly, and preparing finished products for shipment.
Fire Sprinkler Technician Helper Marmic Fire & SafetyFire Sprinkler Technician HelperTulsa, OklahomaFull timeAs we’ve expanded - bringing more than 30 businesses into the Marmic family in just the past few years - we’ve built a culture where skilled technicians and industry experts can thrive, share their knowledge, and create lasting careers. Our teams install, inspect, and repair critical systems in industrial and corporate facilities, hospitals, schools, retail environments, and more—protecting lives and property every step of the way.
Diesel Technician Mobile RyderDiesel Technician MobileOKLAHOMA CITY, OklahomaFull timePreventive Maintenance: Proper lube techniques; Minimal tire inspection; Brake check/applied stroke; Battery check; Under vehicle check/loose components; Initial Fault code identification; All PMs (PM298) including C supplements to exclude overheads, engine brake overhauls, DPF servicing, clean doser injector, servicing ArvinMeritor unitized hubs, inspect Lece Neville alternator brushes, inspect modulator system for proper operation, inspect/adjust shift selector cable, pop test Isuzu injectors. Tire and Wheel Maintenance: Perform air pressure checks; Check tread depth; Identify tires that need to be changed or repaired; Perform tire P.M. checks; Replace tire and wheel assemblies; Mount/dismount and rotate tires; Perform tire/wheel checks/repairs per (TW298).
Commercial Service Technician Pilot Travel Centers LLCCommercial Service TechnicianMuskogee, OKPilot Company supports a growing portfolio of brands with expertise in supply chain and retail operations, logistics and transportation, technology and digital innovation, construction, maintenance, human resources, finance, sales and marketing. The purpose of this role is to perform installations, preventive maintenance, and repairs on facility HVAC/R systems, food service equipment, plumbing, fuel dispensers, and electrical systems within various food and retail locations.
Associate Construction Materials Testing Technician Olsson AssociatesAssociate Construction Materials Testing TechnicianTulsa, OKYou will document your findings and communicate results to project managers and other stakeholders, facilitating informed decision-making and maintaining the structural integrity and safety of construction projects. • American Concrete Institute (ACI) Grade 1, International Code Council (ICC) Nuclear Gauge, or applicable Department of Transportation/Road certifications, preferred but not required.
Maintenance Technician ArmacellMaintenance TechnicianYukon, OklahomaThe maintenance technician is responsible for maintenance tasks including but not limited to mechanical integrity, electrical troubleshooting, preventative maintenance, training, leading projects and problem solving. Armstrong’s R&D Project Number 54013, developed by three innovators, evolved into ArmaFlex, the world's first flexible, closed-cell elastomeric foam for equipment insulation.
HVAC Refrigeration Service Technician NextechHVAC Refrigeration Service TechnicianOklahoma City, OklahomaFull timeWith more than 2,000 team members and growing, we are the largest HVAC/R service provider in the United States and we continue to push the industry forward. For over 30 years, Nextech has built a reputation rooted in quality, integrity, and value, proudly serving thousands of commercial customers nationwide.
Construction Materials Testing - Lab Technician Olsson AssociatesConstruction Materials Testing - Lab TechnicianOklahoma City, OKPursuant to the California Consumer Privacy Act, as amended by the California Privacy Rights Act (collectively, the "CCPA"), this notice explains Olssons practices regarding the collection, use, and disclosure of personal information for job applicants residing in California. The ideal candidate brings prior experience working in a CMT lab-particularly with soils and asphalts, is eager to learn, grow, and take on new challenges.
Senior Construction Materials Testing Technician Olsson AssociatesSenior Construction Materials Testing TechnicianTulsa, OKPursuant to the California Consumer Privacy Act, as amended by the California Privacy Rights Act (collectively, the "CCPA"), this notice explains Olsson's practices regarding the collection, use, and disclosure of personal information for job applicants residing in California. You will document your findings and communicate results to project managers and other stakeholders, facilitating informed decision-making and maintaining the structural integrity and safety of construction projects.
Commercial Refrigeration Technician NextechCommercial Refrigeration TechnicianTulsa, Oklahoma$35 / hourCompany Vehicle: Hit the road in a fully equipped van, gas card includedStart Your Day from Home: Dispatched directly from home for daily convenienceGet Paid for All Your Time: Paid port-to-port travel means no unpaid downtimeTool Allowance: Keep your gear sharp - we've got you coveredProfessional Growth: Paid training, certification support, and education reimbursementOutstanding Benefits: Travels to job sites in assigned service area and works with assigned Dispatcher(s) to ensure schedule is maintained and delays are properly communicated to customers.
Research Technician I/II/III/IV - Lessard Lab Oklahoma Medical Research FoundationResearch Technician I/II/III/IV - Lessard LabOklahoma City, OKThe Lessard Lab is seeking a Research Technician at either the I, II, III or IV level to perform cell and molecular biology techniques including, but not limited to, in vitro cell culture (mammalian cells, primary cells, and human inducible pluripotent stem cells (hiPSCs)), CRISPR genome editing, flow cytometry, next-generation sequencing library preparation, and single cell sequencing and spatial transcriptomics technologies (i.e., latest 10X Genomics platforms). Experience using 10X Genomics Single Cell Technologies (scFLEX/scFFPE, 5’CITEseq, Xenium, etc.) and other high-throughput sequencing approaches (ATAC-seq, RNA-seq, SMART-seq, Perturb-seq, HiC, etc).
Research Technician IV - Lessard Lab Oklahoma Medical Research FoundationResearch Technician IV - Lessard LabOklahoma City, OKThe Lessard Lab is seeking a Research Technician IV to perform advanced cell and molecular biology techniques including, but not limited to, in vitro cell culture (mammalian cells, primary cells, and human inducible pluripotent stem cells (hiPSCs)), CRISPR genome editing, flow cytometry, next-generation sequencing library preparation, and single cell sequencing and spatial transcriptomics technologies (i.e., latest 10X Genomics platforms). Eight (8) to ten (10) years of hands-on experience using 10X Genomics Single Cell Technologies (scFLEX/scFFPE, 5CITEseq, Xenium, etc.) and other high-throughput sequencing approaches (ATAC-seq, RNA-seq, SMART-seq, Perturb-seq, HiC, etc).
Powertrain Technician CanooPowertrain TechnicianOklahoma City, OKAny unsolicited resumes or candidate profiles submitted in response to our job posting shall be considered the property of Canoo Inc. and its subsidiaries and are not subject to payment of referral or placement fees if any such candidate is later hired by Canoo unless you have a signed written agreement in place with us which covers the applicable job posting. Canoo's success is the direct result of our disciplined application of our core operating principles and drills, which are based on three main principles: Think 80/20 ("Important versus less important"), Act 30/30 ("Reduce waste and increase output"), and Live 90/10 ("We have each other's back").
Field Service Diesel Technician Trinity Employment SpecialistsField Service Diesel TechnicianTulsa, OK$25–$40 / hourThis position requires someone who can manage service calls with minimal supervision, troubleshoot complex mechanical systems, and maintain a professional relationship with customers while representing the company in the field. Frequently bend, stoop, kneel, crouch, crawl, climb, balance, reach, and perform repetitive hand movements using tools.
Electrical Technician Trinity Employment SpecialistsElectrical TechnicianTulsa, OK$20–$40 / hourRequires frequent bending, stooping, kneeling, crouching, crawling, climbing, balancing, lifting, carrying, and reaching or handling with arms, hands and fingers. Testing solid state circuitry to find defective parts in digital and analog equipment, specifically cell prox circuits for frequency and 4-20 milliamp control circuits.
Electronics Technician - (Medical Devices) Nesco Resource, LLCElectronics Technician - (Medical Devices)Oklahoma City, OK$21 / hourPerforms routine troubleshooting and repair of electromechanical medical instruments and assemblies using released procedures, drawings, blueprints, etc. to meet established quality and performance metrics. Responsibilities : • (70%) Diagnose, troubleshoot, repair, calibrate, adjusts, and tests analog/digital electromechanical medical instruments to established procedures and specifications.
NewTechnician I Easy Ice LLCTechnician IOklahoma City, OKWork Environment and Physical Demands: The employee is often required to stand; walk; sit; use ladders; use hands to manipulate, handle, or feel surfaces, parts and tools; reach with hands and arms and stoop, kneel, crouch, or crawl. A successful Technician I will drive the following outcomes: Increase the effectiveness and efficiency of the customer service experience by cleaning, installing and or repairing machines properly the first time, every time.
Facility Maintenance Technician U-Haul International IncFacility Maintenance TechnicianTulsa, OKThe states in which U-Haul will decline to hire nicotine users are: Alabama, Alaska, Arizona, Arkansas, Delaware, Florida, Georgia, Hawaii, Idaho, Iowa, Kansas, Maryland, Massachusetts, Michigan, Nebraska, Pennsylvania, Texas, Utah, Vermont, Virginia, and Washington. Physical Demands: The work requires some physical exertion such as long periods both indoors and outdoors while remaining stationary, traversing spaces, repositioning to reach and use tools and moving a minimum of 50 lbs assisted or unassisted.
Assembly Technician / Night Shift (8:00 pm to 6:00 am) Danfoss A/SAssembly Technician / Night Shift (8:00 pm to 6:00 am)Shawnee, OKProperly select, assemble, and identify characteristics of parts involving the pressing bearings, fitting and alignment of shafts, seating seals, spacers, and retainers, and visually inspect parts for defects and adjust/align parts for proper fit as needed. Additionally, you can freely decide and change any time whether you accept cookies or choose to opt out of cookies to improve the website's performance, as well as cookies used to display content tailored to your interests.
Assembly Technician / 1st Shift Danfoss A/SAssembly Technician / 1st ShiftShawnee, OKOur solutions are used in such areas as refrigeration, air conditioning, heating, power conversion, motor control, industrial machinery, automotive, marine, and off- and on-highway equipment. Properly select, assemble, and identify characteristics of parts involving the pressing bearings, fitting and alignment of shafts, seating seals, spacers, and retainers.
Assembly Technician / 3rd Shift Danfoss A/SAssembly Technician / 3rd ShiftShawnee, OKOur solutions are used in such areas as refrigeration, air conditioning, heating, power conversion, motor control, industrial machinery, automotive, marine, and off- and on-highway equipment. Properly select, assemble, and identify characteristics of parts involving the pressing bearings, fitting and alignment of shafts, seating seals, spacers, and retainers.
Assembly Technician / 2nd Shift (3:00 pm to 11:00 pm) Danfoss A/SAssembly Technician / 2nd Shift (3:00 pm to 11:00 pm)Shawnee, OKOur solutions are used in such areas as refrigeration, air conditioning, heating, power conversion, motor control, industrial machinery, automotive, marine, and off- and on-highway equipment. Properly select, assemble, and identify characteristics of parts involving the pressing bearings, fitting and alignment of shafts, seating seals, spacers, and retainers.
NewAviation Dimensional Inspection Technician Kratos DefenseAviation Dimensional Inspection TechnicianBristow, OKKratos Defense & Security Solutions, Inc. (NASDAQ:KTOS) develops and fields transformative, affordable technology, platforms, and systems for United States National Security related customers, allies, and commercial enterprises. Consolidated Turbine Specialists, LLC (CTS), a Kratos' company, is looking for an Aviation Dimensional Inspection Technician to work onsite at their Bristow, OK facility.
Maintenance Technician I - 2nd Shift DanaherMaintenance Technician I - 2nd ShiftDuncan, OklahomaThis includes, but is not limited to, motors, pumps, relays, circuit breakers, electronic machine controls and circuits, computers, printers, and other equipment. Cytiva, a Danaher operating company, offers a broad array of comprehensive, competitive benefit programs that add value to our lives.
Associate Construction Materials Testing Technician OlssonAssociate Construction Materials Testing TechnicianOklahoma City, OklahomaPursuant to the California Consumer Privacy Act, as amended by the California Privacy Rights Act (collectively, the “CCPA”), this notice explains Olsson’s practices regarding the collection, use, and disclosure of personal information for job applicants residing in California. You will document your findings and communicate results to project managers and other stakeholders, facilitating informed decision-making and maintaining the structural integrity and safety of construction projects.
Senior Construction Materials Testing Technician OlssonSenior Construction Materials Testing TechnicianTulsa, OklahomaPursuant to the California Consumer Privacy Act, as amended by the California Privacy Rights Act (collectively, the “CCPA”), this notice explains Olsson’s practices regarding the collection, use, and disclosure of personal information for job applicants residing in California. You will document your findings and communicate results to project managers and other stakeholders, facilitating informed decision-making and maintaining the structural integrity and safety of construction projects.
Associate Construction Material Testing Technician (Travel Required) OlssonAssociate Construction Material Testing Technician (Travel Required)Oklahoma City, OKPursuant to the California Consumer Privacy Act, as amended by the California Privacy Rights Act (collectively, the "CCPA"), this notice explains Olsson's practices regarding the collection, use, and disclosure of personal information for job applicants residing in California. You will document your findings and communicate results to project managers and other stakeholders, facilitating informed decision-making and maintaining the structural integrity and safety of construction projects.
Senior Construction Materials Testing Technician (Travel Required) OlssonSenior Construction Materials Testing Technician (Travel Required)Oklahoma City, OKPursuant to the California Consumer Privacy Act, as amended by the California Privacy Rights Act (collectively, the "CCPA"), this notice explains Olsson's practices regarding the collection, use, and disclosure of personal information for job applicants residing in California. You will document your findings and communicate results to project managers and other stakeholders, facilitating informed decision-making and maintaining the integrity and safety of construction projects.
Construction Materials Testing - Lab Technician OlssonConstruction Materials Testing - Lab TechnicianOklahoma City, OKThe ideal candidate brings prior experience working in a CMT lab—particularly with soils and asphalts, is eager to learn, grow, and take on new challenges. Pursuant to the California Consumer Privacy Act, as amended by the California Privacy Rights Act (collectively, the "CCPA"), this notice explains Olsson's practices regarding the collection, use, and disclosure of personal information for job applicants residing in California.
Fire Sprinkler Technician Marmic Fire & SafetyFire Sprinkler TechnicianTulsa, OklahomaFull timeAbility to perform physical labor, including lifting and moving equipment over 50 lbs, and working in challenging positions such as climbing ladders, using high lift equipment, and working in confined spaces. As we’ve expanded - bringing more than 30 businesses into the Marmic family in just the past few years - we’ve built a culture where skilled technicians and industry experts can thrive, share their knowledge, and create lasting careers.
Hood Cleaning Technician Marmic Fire & SafetyHood Cleaning TechnicianOklahoma City, OklahomaAs we’ve expanded - bringing more than 30 businesses into the Marmic family in just the past few years - we’ve built a culture where skilled technicians and industry experts can thrive, share their knowledge, and create lasting careers. Our teams install, inspect, and repair critical systems in industrial and corporate facilities, hospitals, schools, retail environments, and more—protecting lives and property every step of the way.
New$18/hr. - Construction Field Technician Trainee Building & Earth Sciences, Inc.$18/hr. - Construction Field Technician TraineeTulsa, OKLearn to document like a detective, study rocks and soil mechanics like a geologist, and be the boots on the ground for new and exciting construction projects in your area and all over the Southeast! Your daily schedule can change from day to day and you must be able to accommodate a flexible working schedule and have reliable transportation to and from the branch office at all hours of the day if needed.
New$17/hr. - Construction Field Technician Trainee Building & Earth Sciences, Inc.$17/hr. - Construction Field Technician TraineeOklahoma City, OklahomaLearn to document like a detective, study rocks and soil mechanics like a geologist, and be the boots on the ground for new and exciting construction projects in your area and all over the Southeast! Your daily schedule can change from day to day and you must be able to accommodate a flexible working schedule and have reliable transportation to and from the branch office at all hours of the day if needed.
Research Technician I - Griffin Lab (Part-Time) Oklahoma Medical Research FoundationResearch Technician I - Griffin Lab (Part-Time)Oklahoma City, OKLocated in Oklahoma City, a city that offers a dynamic and flourishing downtown area, with low cost of living, short commute times and a diversified economy, OMRF has been voted one of the Top Workplaces since the inception of the award. OMRF is dedicated to understanding and developing more effective treatments for human diseases, focusing on critical research areas such as Alzheimers disease, cancer, lupus, multiple sclerosis, and cardiovascular disease.
Forestry Research Technician BS4980 The OSU/A&M SystemForestry Research Technician BS4980Stillwater, Oklahoma$17–$24 / hourForest or related plant measurements, operation of complex equipment, experimental design; statistical analysis; proficiency in appropriate software; data logger deployment and programming; ability to operate motor vehicles and work outdoors in difficult terrain; ability to write for a scientific audience; ability to present results to varied audiences. The Field and Research Service Unit (FRSU) is a component of OSU Ag Research that has a mission to conduct research on agriculture, natural resources, rural economies and social issues to increase science-based knowledge and develop technology to improve the lives of Oklahomans.
Service Technician Culligan 245OKService TechnicianTulsa, OklahomaLocal to Tulsa since 1943, we offer state-of-the-art water filtration products, including water softeners, water filtration systems, industrial water treatment solutions, drinking water systems, and whole-house filtration systems. Measure, cut, thread, or bend pipe to the required angle using hand or power tools or machines such as pipe cutters, pipe-threading machines, or pipe-bending machines.
Clinical Pharmacy Technician I - Oklahoma City Option Care Health IncClinical Pharmacy Technician I - Oklahoma CityOklahoma City, OK$16.50–$25.53 / hourBasic level skill in Microsoft Excel (for example: opening a workbook, inserting a row, selecting font style and size, formatting cells as currency, using copy, paste and save functions, aligning text, selecting cells, renaming a worksheet, inserting a column, selecting a chart style, inserting a worksheet, setting margins, selecting page orientation, using spell check and/or printing worksheets). Basic level skill in Microsoft Word (for example: opening a document, cutting, pasting, and aligning text, selecting font type and size, changing margins and column width, sorting, inserting bullets, pictures, and dates, using find and replace, undo, spell check, track changes, review pane and/or print functions).
$17/hr. Construction Field Technician Trainee Building & Earth Sciences Inc$17/hr. Construction Field Technician TraineeTulsa, OKLearn to document like a detective, study rocks and soil mechanics like a geologist, and be the boots on the ground for new and exciting construction projects in your area and all over the Southeast! Your daily schedule can change from day to day and you must be able to accommodate a flexible working schedule and have reliable transportation to and from the branch office at all hours of the day if needed.
New$18/hr. Construction Field Technician Trainee Building & Earth Sciences Inc$18/hr. Construction Field Technician TraineeTulsa, OKLearn to document like a detective, study rocks and soil mechanics like a geologist, and be the boots on the ground for new and exciting construction projects in your area and all over the Southeast! Your daily schedule can change from day to day and you must be able to accommodate a flexible working schedule and have reliable transportation to and from the branch office at all hours of the day if needed.
Entry-Level - Construction Materials Testing Technician Trainee AIMRIGHT Testing & EngineeringEntry-Level - Construction Materials Testing Technician TraineeTulsa, OK$20–$22 / hourWork outdoors in all weather conditions , performing physical tasks (lifting 50–100 lbs, standing, squatting, bending, and kneeling for extended periods). As you gain experience and certifications, you can advance at your own pace: Entry-Level- Construction Materials Testing Trainee ($20.00 - $22.00 per hour) – No experience required; full training provided.
Warehouse Floor Technician Kellermeyer Bergensons Services, L.L.C.Warehouse Floor TechnicianOklahoma City, OK$16.30–$16.58 / hourOur Warehouse Floor Technician positions perform the following duties within designated work areas, as assigned at the beginning of each shift: Perform spot removal, extraction, bonnet cleaning, strip/wax, scrub/recoat, seal/grout, etc. We help industry leaders across a wide range of key verticals-including retail, industrial and logistics, healthcare, education, manufacturing, and more-maintain clean, efficient, and welcoming spaces that support their operations.
Fire Sprinkler Technician Helper Marmic Fire & Safety Co IncFire Sprinkler Technician HelperTulsa, OKAs weve expanded - bringing more than 30 businesses into the Marmic family in just the past few years - weve built a culture where skilled technicians and industry experts can thrive, share their knowledge, and create lasting careers. Our teams install, inspect, and repair critical systems in industrial and corporate facilities, hospitals, schools, retail environments, and more-protecting lives and property every step of the way.
Facility Maintenance Technician U-HaulFacility Maintenance TechnicianTulsa, OKThe states in which U-Haul will decline to hire nicotine users are: Alabama, Alaska, Arizona, Arkansas, Delaware, Florida, Georgia, Hawaii, Idaho, Iowa, Kansas, Maryland, Massachusetts, Michigan, Nebraska, Pennsylvania, Texas, Utah, Vermont, Virginia, and Washington. The work requires some physical exertion such as long periods both indoors and outdoors while remaining stationary, traversing spaces, repositioning to reach and use tools and moving a minimum of 50 lbs assisted or unassisted.
Diesel Technician Mobile Ryder System IncDiesel Technician MobileOklahoma City, OKPreventive Maintenance: Proper lube techniques; Minimal tire inspection; Brake check/applied stroke; Battery check; Under vehicle check/loose components; Initial Fault code identification; All PMs (PM298) including C supplements to exclude overheads, engine brake overhauls, DPF servicing, clean doser injector, servicing ArvinMeritor unitized hubs, inspect Lece Neville alternator brushes, inspect modulator system for proper operation, inspect/adjust shift selector cable, pop test Isuzu injectors. Tire and Wheel Maintenance: Perform air pressure checks; Check tread depth; Identify tires that need to be changed or repaired; Perform tire P.M. checks; Replace tire and wheel assemblies; Mount/dismount and rotate tires; Perform tire/wheel checks/repairs per (TW298).
Experienced Construction Materials Testing Technician AIMRIGHT Testing & EngineeringExperienced Construction Materials Testing TechnicianTulsa, OK$22–$35 / hourAs an Experienced CMT Technician , you will perform field testing, inspections, and observations on residential, retail, commercial, industrial, and municipal projects throughout Oklahoma. This position requires physical work in all weather conditions , daily travel in a company-provided truck , and a flexible schedule that includes occasional night and weekend shifts .