Solving a nonlinear inverse problem of identifying an unknown source term in a reaction-diffusion equation by adomian decomposition method

We consider the inverse problem of finding the nonlinear source for nonlinear Reaction-Diffusion equation whenever the initial and boundary condition are given. We investigate the numerical solution of this problem by using Adomian Decomposition Method (ADM). The approach of the proposed method is to approximate unknown coefficients by a nonlinear function whose coefficients are determined from the solution of minimization problem based on the overspecified data. Further, the Tikhonov regularization method is applied to deal with noisy input data and obtain a stable approximate solution. This method is tested for two examples. The results obtained show that the method is efficient and accurate. This study showed also, the speed of the convergent of ADM.Publisher's Versio

Survey of the relationship between Quality of Work Life with Musculoskeletal Disorders and Hearing Loss

Background and Aims: Measuring and determining the components of quality of work life is one of the most important concerns of human resource management. This study examines the relationship between quality of work life with musculoskeletal disorders (MSDs) and hearing loss as indicators of HSE in an automobile manufacturing company.Materials and Methods: The statistical population of this descriptive-analytical study consists of 392 employees of company who were randomly selected from different departments using Morgan table. Required data was collected using an improved NIOSH quality of work life questionnaire, body map and audiogram.  SPSS software (version 23) was employed for descriptive and regression analyses. All stages of this research were conducted ethically.Results: The findings showed that the mean score for quality of work life was 171.13, ranging from 101 to 212. The greatest sensation of pain, based on the results, was at the end of the lumbar region with a frequency of 40.31 percent and the least was reported in palm left hand with a frequency of 6.38 percent. Furthermore, 6.3% of respondents showed hearing disability. Statistical analyses showed that there is significant relationship between the quality of work life and musculoskeletal diseases (p = 0.000) as well as the quality of work life and the rates of hearing loss (p = 0.000).Conclusion: Also, statistically significant relationship were noticed between the quality of working life and the level of health and safety, mental health, physical health, and employment in a noisy environment . If correct management issues of quality of work life were implemented, improved health indicators and subsequently improved quality of work life could be seen in an organization.Keywords: Quality of Work Life, Musculoskeletal Diseases, Hearing Los

Tight gas sands permeability estimation from mercury injection capillary pressure and nuclear magnetic resonance data

There are several methods to estimate permeability from pore throat sizes and NMR T2 relaxation time. Although most of the methods are well-established and work well for conventional reservoirs they fail to estimate permeability for tight gas sands. The aim of this study was to establish relationships between permeability and pore throat sizes, derived from mercury injection analysis, and NMR T2 relaxation time. Regression analysis was used to achieve a set of relationships between dry gas permeability, porosity and pore throat sizes for 50 tight gas sand samples. Unlike for normal sandstone, pore throat radii corresponding to a mercury saturation of 10% (r10) is the best permeability predictor for tight gas sands. For tight gas sands, NMR T2 relaxation spectra fall on the shorter values corresponding to the smaller pores. This is because pore spaces are significantly reduced both in size and volume due to extensive compaction and cementation. This study shows that using NMR T2peak and multi-regression analysis, permeability can be estimated with high accuracy even in rocks with substantially constricted pore throats

Preliminary study of improving reservoir quality of tight gas sands in the near wellbore region by microwave heating

The formation damages, such as water blocking and clay swelling, in tight gas reservoir have been recognized as severe problems impairing gas production. To remedy these damages, formation heat treatment (FHT) was taken as one of the effective measures by some researchers. In this paper, the effects of microwave heating on the petrophysical properties of sandstone samples has been investigated. A modified commercial microwave oven was used to heat the core plugs and aluminum tubes were used to accommodate tight sandstone samples in order to confine them and reduce their contact with air. After microwave heating, any alterations in the porosity, permeability, texture, structure, mineralogy, and pore size distribution of tight sandstones were investigated by a series of lab experiments. By subjecting tight sandstone samples to microwave, the surface temperature of sandstone can be elevated to approximately 400 °C or more. The intense heat is effective in changing the structure, texture and mineralogy of the sandstone. The shrinkage or decomposition of minerals, which are shown by XRD analysis, and generation of micro-fractures created more spaces in the samples.By employing Automated Permeameter, porosity and permeability are found increased after heating. Nuclear Magnetic Resonance (NMR) and CT numbers of all samples after microwave heating indicate the increase of porosity as well. Moreover, the NMR T2 distribution reveals the smaller pores diminished, so the incremental porosity of short NMR T2 decreased. Micro-fractures generated between grains or in grains due to decomposition of some cement minerals and clay shrinkage, so the amplitude of long NMR T2 increased. The fractures are visible both in X-ray CT images and in Scanning Electronic Microscopy (SEM) images. By comparing with NMR T2 distribution data, it is found that the presence of micro-fractures accounts for the increased population of pores with T2 larger than 10 ms. The numerical simulation of microwave heating in the borehole indicates that the microwave heating is effective to raise the temperature of reservoir rock to approximately 900 °C within 1 day and to remove the water within a distance of 25 cm from the borehole wall. The efficiency of microwave heating can be further improved by optimizing the downhole microwave device

Deformation Spaces, Rescaled Bundles and the Kirillov Character Formula

In this paper, we construct a smooth vector bundle over the deformation to the normal cone $\text{DNC}(V,M)$ through a rescaling of a vector bundle $E\to V$, which generalizes the construction of the spinor rescaled bundle over the tangent groupoid by Nigel Higson and Zelin Yi. We also provide an equivariant version of their construction. As the main application, we recover the Kirillov character formula for the equivariant index of Dirac-type operators. As another application, we get an equivariant generalization of the description of the Witten and the Novikov deformations of the de Rham-Dirac operator using the deformation to the normal cone obtained recently by O. Mohsen.Comment: 28 page

Evaluation of Health, Safety and Environment status using SWOT matrix to provide continuous improvement strategies: A case study in municipality of Qazvin

AbstractBackground and aims: According to the identification of more than one hundred types of jobs in the municipalities, evaluation of adverse factors that each job face with them isn’t possible without systematic model of identifying hazards. In this study, weaknesses, strengths, opportunities and threats (SWOT) to the health, safety and environment (HSE) management was introduced. Based on the results obtained, the HSE situation in Qazvin municipality (12 units) was evaluated.Materials and methods: Two tables concerning internal and external factors are used in the SWOT analysis. The sum of scores in both tables is in the range of 1 to 4, and the status is appraised as positive when the score is higher than 2.5. All necessary arrangements made well in advance. Ethical issues were also all considered in all stages of research.Results: The scores obtained in the evaluation of internal and external factors were often less than 2.5. The mean scores of internal and external factors evaluation were 2.37 and 2.42, respectively. The highest score in internal factors was 2.95 belonging to Qazvin municipality's parks and green spaces. Also, the highest score of external factors was 3.1 belonging to the organization of transport and traffic administration of Qazvin municipality.Conclusion: The HSE situation in half of Qazvin municipality's units was considered undesirable based on SWOT matrix (district 4); and therefore, they should adopt defensive strategies to improve their HSE status. Other organizations were in the shift (2 units) or diversification (4 units) strategies. The results ofpresent study revealed that SWOT analysis can be used as an effective management tool to determine thestatus and management of HSE as well as continuous improvement strategies.Keywords: HSE, Strategic management, External factors, Internal factors, SWOT matrix, Qazvin municipalityFor downloading the full text please click her

Numerical modelling of microwave heating treatment for tight gas sand reservoirs

Formation Heat Treatment (FHT) has been proved effective in removing water phase and creating micro-fractures in the near wellbore area previously. In order to improve the cost and time efficiency of FHT, microwave heater is considered as an alternative in this paper, and its feasibility in FHT is discussed in this paper. Numerical simulation is carried out to investigate the effects of microwave heating on reservoir quality and gas production. It is found that the water phase can be effectively removed by microwave heating, as a result, the relative permeability to gas increased significantly after heating. In terms of gas production rate, the cumulative gas in 90 days in heated well is 4×105 m3 more than the non-heated well. As the most important parameter, the temperature distributions in the reservoir are computed with two methods and their value against the heating depth agree with each other reasonably. On the other hand, the surface temperature variations of tlhree tight sandstone plugs are heated with microwave in the lab and their surface temperatures are carefully recorded against time. Then the laboratory data are compared with simulation results, and they correlate well with each other. The simulation work conducted in this paper shows the promising improvement of gas relative permeability and production by microwave heating

Treatment of a Pigmented Hypertrophic Scar by Low-Level Laser Therapy (LLLT): a Case Report

A hypertrophic scar is defined as an excess healing response that is a dilemma for physicians. Several therapies are available: intralesional corticosteroids, topical treatments, cryotherapy, surgery, radiation, silicone gel dressing and laser therapy.Pulsed-dye, Nd-Yag and CO2 lasers have been used for treatment of keloids and hypertrophic scars but recurrence is common. Recently Low-Level Laser Therapy(aluminum-gallium-arsenide (AlGaAs) Diode 980nm, red light (Mustung, KLO4,Helium Neon 630 nm) and blue light LED lasers have been used for closure of wounds. The aim of this report is to show the effectiveness of these lasers for the treatment of a hypertrophic scar on the forearm of a 40 year-old woman due to burning by gas explosion