Total Equipment Cost Research Articles

Role of BIM technology in enhancing safety analysis of Iraqi oil projects

Oil projects are one of the most common projects which recorded high rates of injuries. Perhaps, due to the complex designs of these projects or poor planning for occupational safety. The research methodology adopts 4D simulation and animation concepts of building information modeling (BIM) technology. This study aims to improve the safety in the Iraqi oil projects, study the impact of applying this technology on the schedule time and cost. The research idea will be applied to one of the Iraqi oil and gas projects. The authors find out that the application of BIM technology leads to accurate identification and assessment of hazards, the ability in providing solutions to mitigate these hazards and solving all safety problems in early stages. The results concluded that applying BIM in the project will increase the working duration of the project about (11 days), and the total cost of safety equipment according to the BIM approach is (36569230 ID). This study is the first of its kind in the application of modern technologies (BIM) in addressing safety problems in Iraqi oil projects.

A Compact and Cost Efficient Multiconverter for Multipurpose Applications

This paper presents a novel single-phase to single-phase multiconverter topology that can be applied in multiple areas. The proposed multiconverter is designed with only two soft power semiconductor switches (e.g. MOSFET or IGBT), four power diodes and a center-tapped transformer which makes it more compact in size, decrease the gate driving complexity, reduce the total equipment costs and enhance the energy conversion efficiency with minimized losses. Furthermore, the utilization of the transformer in the proposed converter mitigates the multiple AC source requirement problems and provides galvanic isolation which increases the reliability of the converter. Moreover, the presented multiconverter is applicable in various areas including electric traction as a speed controller, induction heating, AC and DC variable power supplies, etc. which signify the competence of this converter in energy conversion appliances. However, a comparative analysis of the offered converter with the existing AC-AC converters is also introduced in this paper with respect to the number of components, equipment costs, gate driving complexity, and application areas. In order to evaluate the performance of the proposed multiconverter, the simulation-based results carried out in MATLAB/Simulink are presented and analyzed in this paper with proper descriptions. Finally, a scaled-down prototype is developed in the laboratory to validate the simulation results and the feasibility of the proposed multiconverter.

Energy, exergy and economic analysis of biomass and geothermal energy based CCHP system integrated with compressed air energy storage (CAES)

In this research, a novel combined cooling, heating and power (CCHP) system taking biomass and geothermal energy as co-feeds is proposed, which is mainly consist of four subsections: biomass gasification, compressed air energy storage (CAES), bio-gas turbine power generation and ground source heat pump (GSHP). The compressed air energy storage absorbs off-peak electricity from grid and the high pressure air is utilized to combusted with bio-gas derived from biomass gasification process, the waste heat is utilized by absorption chiller and ground source heat pump. Energy, exergy and economic performances of proposed system are investigated. In the simulation condition, the round trip efficiency and exergy efficiency are 90.06% and 31.52%, respectively; the total investment cost of system equipment is 908008$ and dynamic payback period can be reached at 3.032 year. In the parametric analysis, the effects of key parameters on system performances have been investigated. The system can be reached at an optimum performance when equivalence ratio is 0.275. The energy and exergy efficiency all improve with the increase in air outlet temperature of HX-01, while these criteria shows different tendency with the variations of inlet temperature of gas turbine, inlet and outlet pressure of air storage cavern. Moreover, the dynamic payback period of proposed system increases with the increase in off-peak electricity and biomass cost, whereas decreases with the increase in on-peak electricity cost, hot water cost and cooling cost. The proposed system provides a new way for renewable energy based integration system.

Life cycle assessment and life cycle costing of sanitary ware manufacturing: A case study in China

Sanitary ware industry consumes vast amounts of energy and materials; however, little is known about the environmental impacts and economic costs associated with the production of sanitary ware. Selecting a factory of a leading Chinese sanitary ware company, Huida Co. Ltd., this paper employs a combined “cradle-to-gate” life cycle assessment (LCA) and life cycle costing (LCC) methodology to evaluate the environmental impacts and economic costs related to the production of one tonne of sanitary ware. The LCA results indicate firing and drying are the processes with the greatest environmental impacts, attributing to the combustion of coke oven gas. The LCC results show that casting, body preparation and firing are the greatest contributors to the total equipment, material and energy costs, respectively. The results of sensitivity analysis confirm that increasing fuel efficiency, natural gas usage and recycling rates can reduce the overall environmental impacts, but the total costs would be increased by 13.8% if coke oven gas is fully replaced by natural gas, even considering carbon tax. Based on the findings, recommendations such as using green materials and improving energy efficiency, are provided to promote both the environmental and economic sustainability of sanitary ware production.

Evaluation of a Presurgical Pregnancy Testing Protocol at an Ambulatory Surgery Center

A presurgical pregnancy testing protocol is recommended to prevent the administration of surgery and anesthesia to women of childbearing years who present for surgery with an undetected pregnancy. It is important to determine the compliance, cost analysis, time required, and barriers to complete a presurgical pregnancy testing protocol. Postimplementation qualitative and quantitative evaluation of a presurgical pregnancy protocol. A review of the patient's electronic medical record, survey of the nursing staff, and an administrative interview was conducted 1 year after implementation of the presurgical pregnancy protocol. Overall presurgical pregnancy protocol compliance was 0.7%. The total labor and equipment costs were $19,033 to $30,202 per year. Nurses reported significant time- and patient-related barriers to execute the protocol. A pregnancy testing protocol is a valuable safety measure that faces barriers, which can impede compliance. Through the use of simplified protocols, educational interventions for patients and providers, protocol compliance can be increased.

Simulation of two-step redox recycling of non-stoichiometric ceria with thermochemical dissociation of CO2/H2O in moving bed reactors – Part II: Techno-economic analysis and integration with 100 MW oxyfuel power plant with carbon capture

This paper presents the model of a solar thermochemical looping CO2/H2O dissociation (CL) unit with commercial ceria as the redox oxygen carrier. The CL unit is integrated in an oxy-fuelled combined cycle power plant as an add-on unit to a 100 MW oxy-fuelled natural gas power plant with carbon capture. The efficiency benefit obtained was investigated. A moving bed counter-current reactor model, developed in ASPEN Plus®, consisting of a series of rigorous continuous stirred reactors (RCSTRs) was used for the simulation of both reduction and oxidation reactors of the CL unit. A kinetic subroutine was developed in FORTRAN and linked with each RCSTR for both reduction and oxidation reactions. It is found that the efficiency of the CL unit varies widely with reduction reactor temperature and operating pressure. Considering three different compositions of the feed gas to the oxidation reactor, the CL unit efficiency is obtained as: 35.41% with CO2 only; 30.84% with H2O only; and 35.26% for a mixture of 86% CO2 and 14% H2O. The lower efficiency for H2O-only operation is due to the heat requirement for water vaporization and the higher compression work required for compressing H2 than CO. The maximum solar to electrical efficiency for the whole add-on unit is found to be 25.44% with a reduction reactor operating at a temperature of 1600 °C and 10−7 bar vacuum pressure. With 0.5 m3 reduction reactor volume and 5 m3 oxidation reactor volume, the maximum net electricity produced by the CL add-on unit is 12.85 MWe. Economic analysis revealed that the major contributors to total plant cost are the hydrogen compressor and solar field and tower, which are the 19% and 39% of the total equipment cost, giving a specific overnight capital cost of 12,136 $/kW with an LCOE of 1321 $/MWh with a capacity factor of 21%. The LCOE drops to 628 $/MWh with a carbon tax of 80 $/tonne of CO2 and increased capacity factor of 26%.

Economic Evaluation of Seawater Cooling System Applying Flooded Type Evaporator

The ministry of oceans and fisheries of South Korea promoted the modernization of the purse seine vessels, and the seawater cooling system was proposed as part of the modernization. In the previous study, heat transfer characteristics were analysed with respect to material of tubes to offer fundamental design data of seawater cooling system applying flooded type evaporator by Yoon et al. In this paper, the economic evaluation of the seawater cooling system for comparison with the cooling method using crushed freshwater ice was performed with the net present value method. The initial investment cost of the seawater cooling system was calculated by 181 thousand dollars as the total cost of equipment and facility. The annual benefit was calculated by 47 thousand dollars which subtracts the maintenance cost of the seawater cooling system from the cost of ice and salt. Consequently, the net present value of the seawater cooling system presented positive when the discount rate is lower than 21.4%, which means the seawater cooling system can be considered economical. Moreover, the discount rate has 4.5% as the social discount rate in South Korea, so the net present value of the seawater cooling system has 154 thousand dollars approximately.

OP37 Impact On Uncertainty Of Disaggregating Cost Data

IntroductionEconomic models contain several parameters ordinarily subject to uncertainty. Unlike most other model parameters, costs can constitute numerous distinct components. For example, a surgical intervention can require a variety of disposables and reusable equipment. A micro-costing output may be disaggregated or presented as a total cost. Uncertainty could be applied to individual cost components or to total cost. We aimed to explore how disaggregation of cost data may impact on uncertainty using a case study.MethodsA set of simulations using hypothetical scenarios were developed with uncertainty set at ± 20 percent. The simulations investigated the impact of number of cost components, balance between components, and correlation between them. A cost-utility model from an assessment of robot-assisted radical prostatectomy was analyzed; procedure cost was divided into 32 individual cost components or treated as a total cost.ResultsBased on five equal cost components, uncertainty reduces from ± 20 percent for correlated variables to ± 9 percent for uncorrelated variables. With increasing numbers of uncorrelated cost components, the uncertainty in the total cost decreases markedly. The uncertainty around total robot-assisted surgery procedure equipment costs was ± 19.7 percent when components were correlated and ± 9.4 percent when uncorrelated. The impact on uncertainty in the incremental cost effectiveness ratio (ICER) was negligible but the ranking of parameters in the univariate sensitivity analysis changed.ConclusionsAnalyzing uncertainty by aggregated or disaggregated costs can have implications for presenting uncertainty in costs to decision makers. Applying uncertainty to aggregated costs essentially implies that variation in the cost of individual components is perfectly correlated. By disaggregating cost components they are being treated as uncorrelated, which can substantially reduce uncertainty in the total cost. In this case study we found that although the reduction in uncertainty could be clearly seen in the cost parameter, it had a negligible impact on uncertainty in the ICER.

Система теплопостачання з використанням скидного тепла трансформатора

The task is to use the waste heat of powerful electric transformers for hot water supply in residential and industrial buildings. The high heat of transformers is of low-temperature and therefore requires heaters. The thermal scheme of the hot water supply system with electric transformer and heater - heat pump and electric heater is considered. In the scheme, the heat from the transformer is transmitted to oil, from oil to the heat in the oil-heat exchanger is transferred to water, from water to the evaporator of the heat pump installation (HPI) is transferred to the freon and from the freon to the water of the hot water system is transmitted in the condenser of the HPI. After the HPI condenser, water is heated in the electric heater and is supplied to the consumer. The thermal capacity of the transformer and the temperature of hot water supplied to the consumer are known. The temperature of the water supplied to the heater after the HPI condenser is unknown. According to the criterion of quality of variants with different water temperatures, the total cost of equipment of the scheme of hot water supply system is accepted. The method of determination of the total reduced costs of the hot water supply system with regeneration of waste heat of the transformer is offered. Costs for the hot water supply system are defined as the sum of the costs of heat exchangers, pumps and their consumed electricity, the costs of HPI and consumed electricity of its compressor, the cost of the heater and the consumption of electricity. A computer program for determining the total reduced costs of a hot water supply system with regeneration of the transformer discharge heat has been developed. The results of calculations of the total reduced costs for hot water system options are presented. The variants without HPI with heating of water in the electric heater, with heating of water in HPI and heating it in the electric heater are investigated. The HPI thermal capacities and the compressor drive electrical capacities at different water temperatures from the condensers were determined using the well-known FKW Cycle program. The comparative analysis of the obtained results is performed and it is shown that the cumulative cited costs for the variant of HPI are lower than the cumulative cited costs of the variant without HPI, that the nature of change of the cumulative reduced costs when the temperature of the heated in HPI of water is the same for a wide range of specific costs of HPI and electricity. The lowest total costs shown correspond to the lowest water heating in the HPI and, accordingly, the highest heating in the electric heater.

Techno-economic analysis of CO2 capture from a 1.2 million MTPA cement plant using AMP-PZ-MEA blend

This research covered the rate-based process simulation (ProMax® 4.0) and techno-economic analysis of carbon dioxide (CO2) capture from a 1.2 million metric tonne per annum cement plant using aqueous 2 kmol/m3 AMP-1 kmol/m3 PZ-2 kmol/m3 MEA blend. The waste gas composition for this study was provided by a cement plant from Quebec, Canada. The effect of amine type, energy penalty, and CO2 capture efficiency (50% to 90%) on the capture costs (US$/tonne CO2 and US$/tonne cement) were investigated. Sensitivity analysis on the impact of CO2 capture plant, carbon tax (US$ 20 to US$ 40 per tonne of CO2), CO2 sales price (US$ 10 to US$ 40 per tonne of CO2), energy penalty and CO2 capture efficiency on the cement price was also investigated. Results revealed that at 90% CO2 capture efficiency, the capture costs of AMP-PZ-MEA (US$77.34/tonne CO2 and US$44.94/tonne cement) is lower than that of MEA (US$93.23/tonne CO2 and US$54.17/tonne cement). Results also revealed that the total equipment cost and capital expenditure (CAPEX) of MEA system (US$ 29.76 million and US$ 147.12 million) higher than that of AMP-PZ-MEA blend (US$ 23.39 million and US$ 127.59 million).Cash flow analysis showed that without adding a CO2 capture unit to a cement plant, carbon tax increased the cement price up to 22.9%. However, a combination of the high carbon tax, high CO2 sales price, low energy penalty, and high capture efficiency increased the cement price up to 1.2% for the MEA system but reduced the cement price up to 5% for the AMP-PZ-MEA system. This comprehensive study shows that a cost-effective and energy-efficient amine blend, energy penalty, CO2 capture efficiency, carbon tax, and CO2 sales prices are all integral towards reducing the cement price while significantly reducing the CO2 emissions.

Biogas upgrading by amine scrubbing: solvent comparison between MDEA and MDEA/MEA blend

Biogas upgrading to biomethane has received particular attention in recent years as a key strategy to produce a natural gas-substitute from biomass. Among the available upgrading technologies, amine-based absorption is an interesting option because of its low electric power consumption and very high methane recovery rates. This paper assesses the energy and economic performance of a biogas upgrading process involving chemical absorption with two different aqueous solvent formulations: 50%w MDEA and a 20%w/20%w MDEA/MEA blend. The process performance is evaluated with Aspen Plus and the optimal process conditions are determined with a multi-objective optimization approach targeting the maximum efficiency and minimum specific equipment cost. In the proposed scheme, to make the system energy-self-sufficient, an internal combustion engine burns a fraction of the raw biogas stream to co-generate both the electric power for the upgrading process and the thermal power required for solvent regeneration.Aqueous MDEA turns out to be more efficient (Pareto dominant curve) and less expensive than the MDEA/MEA blend, as a result of the lower regeneration energy (0.94 kJ/Nm3BM/h vs 1.43 kJ/Nm3BM/h) which yields to lower energy consumptions and smaller engine sizes. Even though the cost estimates are subject to a higher degree of uncertainty, the MDEA option features an expected specific total equipment cost as low as 1,550 €/(Nm3BM/h)) vs. 1,850 €/(Nm3BM/h)) for the MDEA/MEA blend.

Scaling up electronic village registers for measuring vital statistics in rural villages in Malawi

Setting: Eighty-three villages without electricity in Mtema Traditional Authority, Lilongwe District, Malawi. Objectives: To describe 1) the expansion of the electronic village register (EVR) to 83 villages in Mtema Traditional Authority, 2) the challenges encountered and changes made to render the system robust and user-friendly, 3) the value propositions developed to increase the system's desirability, and 4) the results of the village register. Design: Descriptive study. Results: After the deployment of the EVR in one village in 2013, the system was extended to 83 villages with modifications to render it more robust and user-friendly. These changes included modifications to the power, connectivity and work stations, better battery security and a single modular electronics panel. Value propositions of the EVR for the village headmen included daily postings of news/sports items and sockets for charging mobile phones and lanterns. Of the 47 559 residents registered, 48% were male, 14% were aged 0-4 years, 43% were aged 15-44 years and 4% were aged ⩾65 years. Between 1 April 2016 and 31 March 2017, 976 births and 177 deaths were recorded. The total equipment cost per village was US$2430. Conclusion: An electronic village birth and death registration system can function in an area with no communication or electricity infrastructure.

Process selection, modelling and optimization of a water scrubbing process for energy-self-sufficient biogas upgrading plants

This study focuses on the techno-economic optimization of an energy-self-sufficient biomethane production plant based on anaerobic digestion of agricultural residues and maize silage and an optimized water scrubbing process. The biomethane production plant features a biogas production system, a water scrubbing upgrading section and an internal combustion engine fed with a fraction of the produced biogas. The engine is properly sized to provide both the electric and thermal power required to operate the whole plant. A thorough literature review is performed to select the most promising water scrubbing layout, which features a scrubber, a flash and a stripping column. Accurate process and preliminary cost models of the main equipment units are developed and validated against literature and industrial data. A techno-economic bi-objective optimization of the upgrading process is then performed in order to determine the set of Pareto optimal solutions with maximum net biomethane recovery efficiency and minimum capital cost. Process optimization is performed with a black-box strategy using the PGS-COM single-objective algorithm and the NSGA-II multi-objective algorithm. The resulting Pareto front achieves net biomethane recovery figures in the range 88.1–89.7% and specific Total Equipment Costs between 0.95 and 1.03 k€/(Nm3BM/h). Compared to the conventional plant configuration, the proposed integration allows to avoid 188 g CO2/Nm3BM emissions and to save between 6.8 and 8.5% of primary energy, with an estimated increase of Total Equipment Cost of approximately 11–13.5% (anaerobic digestion section included).

Subcritical organic ranking cycle based geothermal power plant thermodynamic and economic analysis

This paper is focused both on the thermodynamic and economic analysis of an organic Rankine cycle (ORC) based geothermal power plant. The analysis is applied to a case study of the geothermal field Recica near the city of Karlovac. Simple cycle configuration of the ORC was applied. Thermodynamic and economic performance of an ORC geothermal system using 8 working fluids: R134a, isobutane, R245fa, R601, R601a, R290, R1234yf, and R1234ze(E)], with different critical temperatures are analyzed. The thermodynamic analysis is performed on the basis of the analysis of influence of the operation conditions, such as evaporation and condensation temperatures and pressures, and evaporator and con-denser pinch point temperature difference, on the cycle characteristics such as net power output, and plant irreversibility. The economic analysis is performed on the basis of relationship between the net power output and the total cost of equipment used in the ORC. Mathematical models are defined for proposed organic Rankine geothermal power plant, and the analysis is performed by using the software package engineering equation solver. The analysis reveals that the working fluids, n-pentane and isopentane, show the best economic performances, regardless the evaporation temperatures, while the working fluid R1234yf and R290 have the best thermodynamic performances. In addition, each analyzed working fluid has its corresponding economically optimal condensation temperature (and condensation pressure). Economically optimal pinch point temperature difference of evaporator has different values, depending on the working fluid, while pinch point temperature difference of condenser has similar values for all analyzed working fluids. Analysis results demonstrate that the subcritical ORC geothermal power plant represents a promising option for electricity production application.

Cost of vascular access devices in public hospitals in Queensland.

Objective The aim of this study was to quantify the utilisation of vascular access devices in Queensland public hospitals and their associated cost. Methods Devices were broadly classified into peripheral intravenous catheters, central venous catheters and arterial lines. The number of catheters used was obtained from a central procurement department at Queensland Health and validated using Medicare Benefits Schedule (MBS) claims and/or hospital data from the Australian Institute of Health and Welfare for the same period. Resources consumed included equipment and staff time required to insert and remove catheters. Equipment costs were valued using negotiated hospital prices, and staff time was valued at the fixed industrial award wages in Australia or relevant MBS fees. Device maintenance costs (e.g. dressings) and costs of treating complications were excluded. Results Approximately 2.75million vascular access devices were used in public hospitals in Queensland in 2016, at a total cost of A$59.14million. This comprised a total equipment cost of around A$10.17million and a total labour cost of A$48.85million Conclusion Vascular access is an important component of healthcare expenditure. The present study is the first to characterise and cost vascular access devices in Queensland. Further research is needed on the costs of maintaining device function and of treating complications associated with vascular access. What is known about the topic? The cost of vascular access in Australia has previously been estimated from modelling, using various assumptions, or based on device utilisation in other countries. What does this paper add? For the first time, device utilisation for vascular access in Queensland has been quantified and costed. Results were obtained from reliable sources and validated against other databases. What are the implications for practitioners? Practitioners and managers may now provide accurate estimates about the cost of catheter failure, a potentially preventable problem that affects up to 50% of all catheters placed. Attaching costs to such failure may also stimulate research into how to reduce the problem.

Novel process technologies for conversion of carbon dioxide from industrial flue gas streams into methanol

This research aims to develop efficient process technologies that are capable of converting/utilising CO2 streams into energy-rich liquid products (fuels). This would result in better solutions with near-zero-carbon-emissions level. From an energetic and economic point of view, methanol synthesis from CO2 is a competitive alternate to methanol production from biomass. Our work considers the CO2 balance for the technologies proposed, taking into account all CO2 flows from/to the environment. Flue gas CO2 streams released from electric power stations, steel industry, petroleum industry, and cement industry are good candidates for the developed technologies. Three new processes are developed and modelled for converting CO2 streams into liquid methanol. The total cost of equipment and utility for all process scenarios are evaluated and compared. The energy targets as well as the CO2 emissions (balance) are determined. Heat integration is performed on the best selected process technology. The case study employed for the present work is a power station plant burning natural gas for electricity production with a capacity of 112MW, releasing 328t/h flue gases to the atmosphere, of which CO2 gas accounts for 14%; hydrogen required for CO2 conversion comes from the chlor-alkali industry. The optimum process technology reached in this contribution results in methanol production of 0.625t-per-tonne of CO2 waste gas supply, leading to an annual production of 222,507tons methanol with a profit of 56.55M$/y. Thus, the CO2 release to the environment is cut by about 62%.

Underground gasification of coal and lignite

The underground gasification of coal and lignite is of interest when traditional coal extraction is impossible or unprofitable and also with increasing demand for thermal and/or electric power. In the Soviet Union, at six industrial Podzemgaz stations, beginning in the 1930s, more than 15 million t of coal was processed to obtain more than 50 billion m3 of gas. The South Abinsk station operated from 1955 to 1996, while the Angren station has been operating since 1963. Research on the underground gasification of coal has been largely theoretical, without close connection to industrial practice, and the results are based on mathematical modeling and data from 50–70 years ago. Obviously, Russia’s leading position in the underground gasification of coal has been lost. Russia now lags a number of countries that are making significant investments in the process. Note that, in Russia, despite the obvious benefits of underground gasification of coal, interest in the process has waned, on account of its significant deficiencies: the possibility of gas filtration to the surface; insufficient controllability of coal-bed preparation and thermal processing; the relatively low heat of combustion of the gas produced; and considerable losses of gas and coal underground. Note also the environmental impact of the underground gasification of coal, associated with the deformation of rock, its thermal, chemical, and hydrogeological changes, increase in its temperature, and active chemical pollution of groundwater. An obstacle to the adoption of the underground gasification of coal is the lack of clear ideas regarding the preparation and use of fuel gas. Recommendations for improving the process focus on the design of the underground gas generator and the gasification of the coal bed, without addressing the technology of the underground system, whose cost accounts for ~75% of the total equipment costs. The method proposed in the present work for the preparation of fuel gas from coal challenges the notion that the gas produced in underground gasification of coal should be divided into two products: gas and the tar (hydrocarbons) that forms in the preparation of the gas for combustion. If the specified temperatures are maintained, no condensation of hydrocarbons in the equipment and gas lines is observed, and dry dust removal from the gas may be employed, without complex processing of wastewater and of explosive and toxic materials. That significantly improves the economic and environmental characteristics of the process, Analysis of the results shows that the proposed approach to purifying the fuel gas produced by underground gasification of coal and lignite reduces capital costs in construction of the system by almost half; and the costs of gas production by a factor of 1.7. The time to recoup the initial investment is shortened by 41%; the yield of thermal energy is increased by 10.5%; and annual power output is increased by 151296 MW-h.

Evaluation of different vapor recompression distillation configurations based on energy requirements and associated costs

Distillation with vapor recompression is an emerging technology for reduction of energy consumption of distillation systems. Several configurations of vapor recompression can be used for improving efficiency of a distillation column. Selecting one of these configurations affects the energy requirements and also the equipment needed to carry out the purification process. Thus, inappropriate selection of one configuration might result in huge amounts of energy loss. In this research, six different vapor recompression configurations are applied on a benzene–toluene distillation column. These configurations are simulated using Aspen HYSYS simulator and economically evaluated using Aspen Economic Evaluation software. Based on energy and hot and cold utility requirements, annual operating costs, total capital costs, utility costs and equipment costs of different configurations, the best vapor recompression configuration is selected.

Arthroscopic Transosseous Rotator Cuff Repair

Objectives:Health expenditures in the United States are outpacing national income, and affordability has become a major policy issue. Over 500,000 rotator cuff repairs (RCR) are performed annually in the United States making RCR a potential source of cost savings. Arthroscopic trans-osseous equivalent (TOE) repair using a double row of anchors has shown superior biomechanical strength compared to other techniques, but at a higher cost. The arthroscopic transosseous (TO) repair is a novel technique allowing arthroscopic rotator cuff repair to be performed without suture anchors. Arthroscopic TO repair may be a means to provide similarly excellent patient outcomes while lowering the cost of care. The primary purpose is to compare the price differential and time of surgery for an arthroscopic rotator cuff repair using anchorless TO repair verses an anchor trans-osseous equivalent (TOE) repair. A secondary purpose of the study was to evaluate outcomes at 6 months postoperatively.Methods:A prospective, case-controlled study evaluating arthroscopic rotator cuff repair using two techniques was performed. The study group consisting of 21 patients undergoing TO repair was compared to a control group consisting of 22 patients undergoing TOE repair. The groups were controlled for size of tear, biceps treatment, acromioplasty, distal clavicle excision, and labral pathology. The primary outcome measures were surgical time as well as total cost of implants and equipment for each surgery, determined by an independent third party, Atlanticare Hospital. Secondary outcomes were changes in the SST, VAS, and SANE scores.Results:Mean total surgical implant/equipment cost per procedure for TOE repair was $2348.03 (SD 490.30) and for TO repair was $1204.97 (SD 330.69; p<0.0001). Mean cut to close time for TOE repair was 85 minutes (95% CI is 77-90) verses 74 (95% CI = 71-98) for TO repair. A log rank test revealed no difference in time (p =0.95). A linear regression model was developed to evaluate the change in SST, VAS, and SANE scores from pre-op to 6 months follow-up. Our study was underpowered but no difference in outcome was observed.Conclusion:Arthroscopic TO rotator cuff repair is a cost savings and time neutral technique compared to TOE repair. A mean of $1100 can be saved in surgical cost per case. In a country that performs over 500,000 RCRs annually, utilizing a TO repair technique can provide substantial cost savings to the healthcare system.

Model for economic replacement time of mining production rigs including redundant rig costs

Purpose – The purpose of this paper is to present a practical model to determine the economic replacement time (ERT) of production machines. The objective is to minimise the total cost of capital equipment, where total cost includes acquisition, operating, maintenance costs and costs related to the machine’s downtime. The costs related to the machine’s downtime are represented by the costs of using a redundant machine. Design/methodology/approach – In total, four years of cost data are collected. Data are analysed, practical optimisation model is developed and regression analysis is done to estimate the drilling rigs ERT. The artificial neural network (ANN) technique is used to identify the effect of factors influencing the ERT of the drilling rigs. Findings – The results show that the redundant rig cost has the largest impact on ERT, followed by acquisition, maintenance and operating costs. The study also finds that increasing redundant costs per hour have a negative effect on ERT, while decreases in other costs have a positive effect. Regression analysis shows a linear relationship between the cost factors and ERT. Practical implications – The proposed approach can be used by the decision maker in determining the ERT of production machines which used in mining industry. Originality/value – The research proposed in this paper provides and develops an optimisation model for ERT of mining machines. This research also identifies and explains the factors that have the largest impact on the production machine’s ERT. This model for estimating the ERT has never been studied on mining drilling rigs.