Method Research Articles

Psychiatric Manifestations in the Patients of Obstructive Sleep Apnea at Tertiary Care Center of Northern India

Aim: The aim of the study is to understand the role of anxiety and depression in obstructive sleep apnea (OSA) patients. Patients and Methods: This prospective, observational study was conducted at King George's Medical University, Lucknow, Uttar Pradesh, India, from September 2011 to August 2012. Seventy-one patients were enrolled in the study after obtaining informed written consent. Polysomnography (PSG) was performed to confirm OSA, and the psychiatric features were determined using the Hospital Anxiety and Depression Scale score. Results: A total of 71 individuals were enrolled in the study, and after exclusion, 48 individuals had participated in PSG. Of the 48 patients, 44 (91.67%) had shown OSA with PSG. From 44 OSA-diagnosed patients, 10 (22.73%) patients were diagnosed of having psychiatric manifestations (50% with depression, 30% with anxiety, and 20% having features of both depression and anxiety). No significant difference was found in between those with psychiatric features than that those without in body mass index (mean ± standard deviation [SD]: 32.38 ± 7.17 and 31.64 ± 3.93, P = 0.610), Epworth's sleepiness scale score (mean ± SD: 13.20 ± 4.71 and 11.88 ± 5.63, P = 0.505), apnea/hypopnea index (mean ± SD: 48.01 ± 31.71 and 37.81 ± 22.84, P = 0.263), average saturation (mean ± SD: 92.19 ± 4.37 and 91.74 ± 4.38, P = 0.774), and lowest saturation (mean ± SD: 74.50 ± 11.97 and 74.32 ± 11.97, P = 0.968), respectively. Conclusion: Although patients with OSA must be screened for psychiatric manifestations, the severity of OSA is not directly related to the severity of psychiatric features.

Study of Nocturnal Oxygen Desaturation in Chronic Obstructive Pulmonary Disease Patients

Background: Abnormal sleep architecture with decreased rapid eye movement sleep and arousals during the periods of nocturnal oxygen desaturation (NOD) are seen in patients with chronic obstructive pulmonary disease (COPD) with significant consequences. This study was done to evaluate the prevalence of NOD and other sleep-related disorders in COPD patients. Patients and Methods: This prospective cross-sectional study was conducted in the sleep laboratory of our tertiary center over 1 year. Fifty COPD patients were enrolled in this study. They were classified into mild COPD and moderate COPD, according to the Global Initiative for Obstructive Lung Disease (GOLD) classification. Complete history, physical examination, and relevant laboratory investigations were taken. All patients were subjected to overnight polysomnography. Results: Eight patients had mild COPD, whereas 42 patients had moderate COPD. Mean sleep efficiency was decreased with an average of 71.08% with a significant difference between mild and moderate COPD cases. Minimal SpO2, average SpO2, SpO2

A Study of Outcome of Noninvasive Ventilatory Support in Acute Respiratory Failure

Introduction: Noninvasive ventilation (NIV) is often used in acute respiratory failure to prevent endotracheal intubation and its complications. Various factors influence favorable outcome for NIV. Aim: To assess the outcome of NIV in acute respiratory failure and to determine predictors of positive outcome. Patients and Methods: This was an observational study of 4 years where 110 patients with acute respiratory failure requiring NIV were included. Data of history, examination, investigations, and clinical outcome of all patients were recorded. The outcome was divided in two categories depending upon whether patients improved or required invasive ventilation. Results: Of 110 patients, there were 78 men with a mean age of 64.24 years and 32 women with a mean age of 56.59 years. The causes of acute respiratory failure were acute exacerbation of chronic obstructive pulmonary disease (COPD) (61.81%), bronchial asthma (9.09), pneumonia (22.72%), tuberculosis (2.72%), interstitial lung disease (1.81%), and pulmonary artery hypertension (0.9%). Among them, 81 (74%) patients improved. Patients who had acute respiratory failure due to COPD (P 3 days (P = 0.001). Conclusions: COPD patients with acute respiratory failure respond well to NIV. Improvement in pH, PCO2, and PO2 within or at 24 h of NIV predicts successful outcome. Requirement of prolonged NIV leads to poor outcome.

An Efficient High-Order-Moment-Based Reliability Method Combining the Maximum Likelihood Point and Cubic Normal Transformation

Moment-based methods can measure the safety degrees of mechanical systems affected by unavoidable uncertainties, utilizing only the statistical moments of random variables for reliability analysis. For the conventional derivation of the first four statistical moments based on the second-order Taylor expansion series evaluated at the most likelihood point (MLP), skewness and kurtosis involve the higher fourth raw moments of random variables and thus are unfavorable for engineering applications. This paper develops new computing formulae for the first four statistical moments which require only the first four central moments of random variables, and the probability distribution of the performance function is approximated using cubic normal transformation. Several numerical examples are given to demonstrate the accuracy of the proposed methods. Comparisons of the two proposed approaches and the maximum entropy method (ME) are also made regarding reliability assessment.

SIMULASI BEBAN RANGKA PADA MESIN PENGGILING SEKAM PADI MENGGUNAKAN PERANGKAT LUNAK

One of the main components in the rice husk grinding machine is the frame. The frame is the most important fundamental part, especially for use in machinery, because the function of the frame is as a support for the components themselves, and is able to withstand axial, normal and moment forces to maintain stability in the machine. The strength of the frame depends on the shape or type of construction which is able to withstand torsional loading from the engine and also withstand the shock that is given when the engine moves. So the purpose of this study is to find out how to simulate the loading of the frame on a rice husk grinding machine using SolidWorks software, and to know the comparison of theoretical calculations and simulations for 3 material variations on the frame of a rice husk grinding machine in a static state. The method used is the Finite Element Method (MEH), MEH with software can determine the loading points. From this test, researchers can find out which points have a minimum load, a medium load, and a maximum load. The results of the analysis provide the safety value of original and processed materials, changes in materials can be concluded which material is more ideal. The results of this study are that among AISI 1010, ASTM A36, and AISI 1045 materials, the best material is AISI 1045 material because it has the greatest safety factor value of 12.15.

Фазовые переходы сгущенного молока с сахаром в расширенных температурных диапазонах хранения

Sweetened condensed milk is a popular food in various climatic zones, including those regions where average winter temperature falls below –30°C. Such low temperatures can trigger crystallization because they disrupt the native structure of biopolymers. These processes spoil the quality of sweetened condensed milk. However, no scientific publications feature the cryoscopic temperature of sweet condensed milk or systematize the data on its low-temperature storage.
 Sugar, sugar-milk, and milk solutions of various concentrations were frozen to determine their cryoscopic temperature by the thermographic method using a Testo 176T4 meter (Germany) with K-type probes (NiCr-Ni) at –78.5°C. The phase transitions were studied using a Mettler Toledo DCS 822e DSC analyzer.
 The nucleation temperature, the cryoscopic temperature, and the subcooling degree depended on the concentration and the type of the solute. For sugar solutions, the cryoscopic temperature varied from –0.4 ± 0.1 to –6.4 ± 0.1°C; for sugar-milk solutions, it ranged from –2.1 ± 0.1 to –10.9 ± 0.1°C; for whole milk solutions, it was from –0.4 ± 0.1 to –4.6 ± 0.1°C. The thermographic method failed to obtain the phase transition and the cryoscopic temperature in analogue models of sweetened condensed milk. The loss of fluidity was about –30°C when the storage time exceeded 2 h. This effect was comparable to 54 min of storage at –35°C. The differential scanning calorimetry meth od showed that the phase transition occurred at –80°C.
 This research opens new prospects for differential scanning calorimetry studies of phase transitions in condensed sweetened dairy products.

상권 방문특징과 상권 포지셔닝 맵에 대한 탐색적 연구: 대응일치분석과 다차원척도법의 절차적 적용

The process of identifying the characteristics of the trading area to be analyzed and analyzing the difference from the competitive trading area is an essential prior task in establishing marketing strategies to revitalize a trading area. However, most trading area studies, so far, have relied heavily on quantitative descriptive statistics of a trading area itself or the empirical insight of researchers. As a result, objective and valid research methodologies for analyzing the characteristics of trading area were very deficient and there were few research attempts to analyze differences from competing trading areas based on the perception differences of visitors. To achieve the objectives of this study, the following procedures were carried out. First, a questionnaire survey was conducted for consumers who frequently or accustomed to visiting the trading areas of Konkuk University Station (K TA), Hongik University Station (H TA), and Gangnam Station (G TA), which were selected as the target trading areas. Next, through using the chi-square test, it was verified whether there were significant differences between the three trading areas and the eight categories, such as the origin of the visit and the type of visiting companion. The differences in the association of visitors between trading areas and categories were plotted in diagrams. And by using the Multiple Correspondence Analysis (MCA), which is an extension of CA, the perception differences of visitors were visualized on the positioning map with respect to the relationship between the three trading areas and gender/type of visit companion, and gender/age group. In addition, by using the Multidimensional Preference Analysis (MDPREF), one of the types of Multidimensional Scale Methods (MDS), the difference in perception of visitors is analyzed through a positioning map on the relationship between three trading areas, the purpose of the visit, major use business types, and information sources. A procedural methodology for the creation of a trading area positioning map was presented. The results are as follows. First, there were significant differences in the categories of the origin of visit, type of visiting companion, average spending amount, visiting transportation, and return transportation in the three trading areas. Second, the MCA results verified that the K TA is is favored by the female and the 20s, the H TA by the male and the 30s, and the G TA by the 40s. Finally, the results of the MDPREF analysis are as follows. First, in terms of the perception of visitors, the H TA was recognized as a mixed trading area with multi-dimensional purposes, not specific factors, unlike the other two trading areas. Second, in the relationship between the three trading areas and the major business type used, the three trading areas were not differentiated and were found to be in fierce competition. Third, in terms of information sources, there was no difference in the information sources used by visitors to the three trading areas, and it was found that visitors preferred to obtain informations through Internet search, neighborhood recommendation, and SNS. The results provide trading area marketers with a theoretical methodology to build effective trading area marketing strategies including market segmentation and customer targeting through the objective identification of visit characteristics and analysis of perceptual differences of trading area visitors. In addition, the results suggest a theoretical and procedural methodology for arranging the trading area positioning map that is differentiated as a competitive strategy and repositioning the specific trading area by improving the visitor

Molecular dynamics simulation of adsorption and diffusion of partially hydrolyzed polyacrylamide on kaolinite surface

In tertiary oil recovery in oilfields, polymer solutions (partially hydrolyzed polyacrylamide) are often used for enhancing oil recovery. In view of the limitations of the current indoor flooding experiments, such as the limited scope of application and many assumptions, it is difficult to deeply reveal the mechanism of polymer flooding. In this paper, the molecular dynamics simulation method (MD) is used to establish an interaction model based on the construction of rock model, polymer molecular model and polymer solution system model to simulate the transport of polymers in nanopores from the microscopic level, and to study molecular. The interaction between them is described, and their diffusion and adsorption behaviors and viscoelastic properties are described, which provides a theoretical basis for the optimization of oil-displacing agents and the characterization of macro-rheological properties and flow parameters.

Magneto-optical property of Ce-substituted YIG films fabricated by metal–organic deposition method

The metal–organic deposition method (MOD) fabricated cerium-substituted yttrium iron garnet (Ce:YIG, CexY3-xFe5O12) films with chemical composition Ce : Y : Fe=1.0:2.0:5.0. We determined the components of the dielectric tensor by measuring the transmittance and reflectance of circularly polarized light. These values are smaller than those obtained by other fabrication methods. Measurements of the cross-section of the samples using scanning electron microscopy (SEM) revealed the layered structures in the backscattered electron (BSE) image, which resulted from the traces of the spin-coating process of the MOD liquid. Energy dispersive X-ray spectroscopy (EDS) measurements revealed a chemical composition of x=0.7. Thus, we consider the small values of the components as the defects in the Ce:YIG crystals and low substitution ratio.

Maternal and Neonatal Tetanus Elimination in Nigeria: A Review of Delivery and Cord Care Practices among Women of Child Bearing Age

Introduction: Maternal and Neonatal Tetanus (MNT) are important causes of maternal and neonatal deaths, and this led the World Health Assembly in 1999 to launch the maternal and neonatal tetanus elimination strategy with a target of 2020 after earlier targets of 2005, 2015 were missed. Tetanus claims tens of thousands of deaths annually with majority of the deaths occurring in Sub-Saharan Africa and Asia. Safe delivery practice is one of the strategies for elimination of MNT and it can be achieved if delivery is handled by a skilled health worker that have adequate knowledge on the care of the umbilical cord. Methods: This study which is a descriptive study that covered 62 high risk Local Government Areas (LGAs) is aimed at determining the delivery practices and cord care practice of Women of Child bearing Age. (WCBA) in sixty–two Local Government Areasin the six States of Ondo, Osun, Ekiti, Imo, Enugu and Ebonyi in Nigeria that were involved in the three rounds of tetanus toxoid vaccination campaign as part of the Nigeria’s Maternal and Neonatal Tetanus Elimination program from 2014 to 2016. Results: A total of 23,860 households were visited by enumerators in all the 1,860 selected clusters surveyed across the 62 high-risk LGAs of the 6 States. Eligible respondents were found in 13,020 of these households (54.6%).Most of the respondents were wives of the household heads, Christians (83.9%), educated with majority attending secondary school (53.8%), employed with majority doing petty trading 30.9% and located in predominantly rural LGAs (74.4%). Across the 62 LGAs, 84.8% of respondents had their delivery handled by doctors, nurses/midwives and CHEW while 76.7% had their delivery handled by doctors and nurses/midwives. On cord care practices the survey results showed that on the average, only 3.1% of women used chlorhexidine with Ebonyi state recording the highest while 79.0% of respondents used methylated spirit for cord care. Conclusion: Sociocultural factors such as maternal education, financial preparedness, marital status, religion has been shown to be strong determinants of Skilled Birth Attendants (SBA) use. SBA usage has a direct effect on maternal and neonatal tetanus elimination as such government is encouraged to support the promotion of formal education for women and women empowerment and autonomy.

Economic Burden of Denatured Alcohol-Induced Burns: A 20-Year Retrospective Study.

Burn care has rapidly improved over the past decades, but health innovations are expensive. We present the first study focusing on the economic burden of exclusive denatured alcohol-induced burns. The goal of this study was to determine costs for the public health system due to inpatients’ burn care because of these specific burns. Moreover, we aimed to observe the incidence of methylated spirit-related burns in the past 20 years. We performed an observational retrospective study in our burn unit including all patients with a denatured alcohol-related burn injury from 1 January 2001 to 31 December 2020. A total of 503 patients with a mean burn size of 24% were hospitalized; the mean annual total costs per patient was €43,879, varying from €31,518 to €63,274.00€; the total costs for denatured alcohol-related burns during the period 2001–2020 was €21,145,076. We noted an increasing incidence of denatured alcohol-related burns and related costs over the years, especially in the last decade. Our results highlight that burns by methylated spirits are still a real and expanding problem. Therefore, authorities should focus on sales rules, characteristics of the containers, and education of people who misuse denatured alcohol, based on historical habits of use. To reduce the socioeconomic costs of burns, future intervention strategies and studies from the dermatology community and burn specialists should focus on prevention programs and prompt wound healing to shorten the length of hospital stay, enable quick return to work, and improve the outcomes of patients with burns.

Influence of the Cable Accessories Installing Method on the Partial Discharge Activity in Medium Voltage Cables

This article proposes a method to modify the construction of a medium voltage (MV) heat shrinkable cable termination in cases of atypical damage to the shields of cross-linked polyethylene (XLPE) insulated cables. The proposed solutions include a modified method of assembling electric field control coating. An attempt was made to check the effect of such damage to the shields of MV cables with XLPE insulation on the level of occurrence of partial discharges within the cable termination. The investigations included testing the XRUHAKXS 1 × 240/25 cable type using the electric method (ME) and high frequency (HF) method with sinusoidal AC test voltage. As a result of the measurements, the values of total charges in the period and phase-resolved partial discharge (PRPD) patterns were obtained. The presented experimental results show the influence of the damage of the semiconducting coating surface on the occurrence of a defect in the cable termination without a modified method of control mantissa pinning. We suggest new methods of assembling MV cable accessories in the case of the presented coating damage in MV cable insulation.

Pectin Production from Biowaste (Fruits & Vegetables) by Crosscurrent Solid-Liquid Extraction Technique

The impact of fruit and vegetable waste is becoming a significant concern for the environment. The biomaterial waste generated from fruit processing industries is very high. When discharged as processed waste, it also increases water pollution. 45% of the total industrial organic pollution originates from food processing industries. These generated wastes are suitable for the production of biochemicals. Pectin is one such biochemical that plays a vital role in reducing the burden on the environment. Pectin helps in the manufacturing of confectionaries. Vegetable waste like beetroot, carrot, beans can also act as a source for pectin production. This study depicts extracting Pectin from mixed fruit pomace waste. Mixed fruit (Orange, Pomegranate, Banana & grapes) pomace waste reacts with 0.1N HCl. This reaction uses a 2-stage crosscurrent solid-liquid extraction technique. For its nature, obtained pectin was tested as calcium pectate using methylated spirit. The filtrate from 2-stage crosscurrent leaching was further dried in an oven. RSM technique helps in optimizing parameters like drying time, temperature, pH, and concentration. The experimental setup generated Pectin gave an efficiency of 11.52% for 22.4g of dried mixed fruit pomace waste.

Bias in regression coefficient estimates when assumptions for handling missing data are violated: a simulation study


 Background
 The purpose of this simulation study is to assess the performance of multiple imputation compared to complete case analysis when assumptions of missing data mechanisms are violated.
 Methods
 The authors performed a stochastic simulation study to assess the performance of Complete Case (CC) analysis and Multiple Imputation (MI) with different missing data mechanisms (missing completely at random (MCAR), at random (MAR), and not at random (MNAR)). The study focused on the point estimation of regression coefficients and standard errors.
 Results
 When data were MAR conditional on Y, CC analysis resulted in biased regression coefficients; they were all underestimated in our scenarios. In these scenarios, analysis after MI gave correct estimates. Yet, in case of MNAR MI yielded biased regression coefficients, while CC analysis performed well.Conclusion
 The authors demonstrated that MI was only superior to CC analysis in case of MCAR or MAR. In some scenarios CC may be superior over MI. Often it is not feasible to identify the reason why data in a given dataset are missing. Therefore, emphasis should be put on reporting the extent of missing values, the method used to address them, and the assumptions that were made about the mechanism that caused missing data.

Psychological symptoms and quality of life in a population living in the "New Towns" of L'Aquila after he 2009 earthquake


 Background: Following the earthquake in L'Aquila of 04.06.2009 more than 65,000 people lost their homes. In order to provide rapid accommodation to those people, the Italian Government implemented the CASE project (Complex Anti-seismic Sustainable Environment-friendly), with the construction of 19 "New town" in the surrounding areas of the city. The New towns are built in rural areas, far from the center of the city, without many basic services. The purpose of this study was to evaluate the prevalence of mental disorders, the levels of psychological symptoms and quality of life in a sample of the population living in such reality.
 Methods: Brief Symptom Inventory (BSI), the Impact of Events Scale-Revised (IES-R), and the Manchester Short Assessment of Quality of Life (MANSA), were used.
 Results: 107 people were interviewed. The mean scores of the GSI of the BSI were 0.70 (SD=0.55). The total score of the IES-R scale was used and the cut-off represented by the 33 value, was exceeded by 59.81% of the sample. The average value was 37.85 (SD=19.49) (range 0-83). 14 people of them (21.88%) obtained an average value ≥ 60. The mean score on the MANSA was 4.5 (SD=0.98), range 1.8-6.3.
 Conclusion: From the results, it appears that this housing solution could be an additional element of trauma that overlaps with that suffered during the quake.

Design Parameters of Cross-Cultural Training (CCT) Programs in Information Technology (IT) Organizations

Objective: To identify key dimensions that are to be considered while designing Cross Cultural Training (CCT). Methods : The data is collected from 421 expatriate employees in the selected IT organizations (Engineers /Managers/ Team Leaders) using an instrument consisting 45 items of nine drivers. The current study adopted Exploratory Factor Analysis (EFA), followed by 2nd order CFA to reveal various input components of training programme that leads to the success of the expatriate training programme. Findings: The factors influencing expatriate training were identified as: Adjustment (AD) factor, Culture factor (CU) and Method (ME) factors which are predominately to be considered for the design of CCT. Novelty: The factors to be considered while designing the CCT has been identified a prior rather finding the effect of such factors during post training evaluation. The results are more authenticated and help IHRM professionals to design CCT which lead to success of expat’s overseas assignment. Keywords: IHRM, Cross Cultural Training (CCT), Adjustment (AD) factor, Culture factor (CU), Method (ME) factors 1

Obsessive Compulsive Tic Disorder: appropriate diagnosis and treatment as key elements to improve health and rationalize use of resources

Background: Obsessive Compulsive Tic Disorder (OCTD) has been described recently as an early onset and highly disabling endophenotype of Tic Disorder and Obsessive Compulsive Disorder. OCTD has a relevant but largely unknown clinical, social and economic burden for patients and their families. Our paper aimed to explore relevant aspects of the burden of OCTD. Methods: we conducted a literature review and a pilot study using retrospective demographic, clinical and economic data of patients with OCTD accessing the Galeazzi Hospital in Milan. Results: the literature review shows the absence of information on OCTD. From the pilot study we analysed data of 30 patients (80.0% male, 36.7% aged from 7 to 13 years, 63.3% aged from 15 to 48 years), 83.0% declared that obsessions and/or compulsions were the most important factors determining their social impairment. Adult patients refractory to drug treatment underwent Deep Brain Stimulation plus drugs. The mean clinical scores at the time of diagnosis indicated a severe condition for both tics and obsessive compulsive components. The mean time elapsed from symptoms onset to diagnosis of OCTD was 5.6 years, reaching up to 11 years in one case. Before reaching the correct diagnosis, different specialists visited the patients several times, 93.3% underwent diagnostic examinations and 86.7% took 2 or 3 different drugs. Ten patients were hospitalised and 8 had received psychotherapy. Discussion: Albeit preliminary, these results show that attention is mandatory for establishing correct diagnosis and treatment guidelines to improve health and rationally spend resources for OCTD.

Design and validation of a self-administered questionnaire to assess knowledge, attitudes and behaviours about Zika virus infection among general population in Italy


 
 
 Background Zika (ZIKV), a flavivirus firstly identified in rhesus monkeys in Zika Forest of Uganda, in 1947, is an emerging virus transmitted mainly by mosquitoes bites. Due to ZIKV adaptation to humans, that can maintain a mosquito-human-mosquito transmission cycle, it is essential to know the attitudes, knowledge and behaviours of general population regarding ZIKV prevention. Our main study aims were to develop and validate a questionnaire administered to the general population, in order to assess attitudes, knowledge and behaviours around prevention and control of Zika infection. Methods A questionnaire was developed based on a comprehensive review of the extant literature, pre-existing questionnaires and experts focus groups. Results The final, validation version of the questionnaire comprised 8 items, with good psychometric properties (Cronbach’s alpha of 0.81). Overall test/re-test concordance was 0.86, ranging from 0.76 to 0.94 according to each item. Conclusion In conclusion, the questionnaire seems to be an appropriate and useful tool to detect cognitive gaps concerning behaviours responsible for possible transmissions of the disease, even in a non-endemic country such as Italy. Future analysis will explore the factorial structure of the questionnaire as well as knowledge, beliefs and attitudes concerning ZIKV among Italian general population.
 

Study ff Interaction Between ADT-C2 Cyclic Peptide (Ac-CADTPPC-NH2) and E-Kadherin Protein Using Docking Molecular Method

Research has been conducted on the study of the interaction between cyclic peptide ADTC2(Ac-CADTPPC-NH2) and E-cadherin protein using the molecular docking method. The aim of this study is to determine the position of the binding site and the energy of interaction between the ADTC2 peptide and the EC1-EC2 domain of E-kadherin. This research was divided into two parts, (1) Preliminary test using molecular dynamics (DM) method with Gromacs v4.5.4 software, (2) interaction of the peptide ADTC2 with EC1-EC2 using the molecular docking method (MD) with Autodock 4.2 software. Docking was performed with the blind dock method on EC1 and EC2 position. In the second step, the gridbox position was reduced based on the binding activity between E-cadherin and peptides. The strongest interaction and Van der Walls bonds were obtained in boxes B, C and D. The results showed that the ADTC2 peptide had a biological activity to inhibit the interaction of E-cadherin...E-cadherin by forming a complex with the EC1-EC2 domain. This inhibition occured by forming two binding sites in the EC1 domain (interaction energies are -23.309 kJ / mol and -26.234 kJ / mol, respectively) and one binding site in the EC2 domain (interaction energies are -22.677 kJ / mol). Based on preliminary tests, it can be proven that the native structure of ADTC2 is cyclic with optimization energy of -52504.78 kJ/mol and very stable from the beginning to the end of DM with an RMSD was <2 Å.

Comparison of evaporation estimation methods for water surface under floating coverage in arid areas

The main purpose of this study is to evaluate evaporation estimation methods for water surfaces under floating coverage in arid areas. The natural water surface evaporation methods (namely, the mass transfer method (MT), Bowen ratio energy balance (BREB) method, Penman method, the Penman-Monteith method (PM), and the Priestley-Taylor method (PT)) are corrected to establish the covered water surface evaporation methods, which are based on the micrometeorology near the covered water surface, energy balance components, and Bowen ratio. The radiation term of the natural water surface evaporation model is corrected by introducing the Bowen ratio of the entire surface, which includes the uncovered water surface and the floating cover surface. The mass transfer coefficient and aerodynamic impedance in the aerodynamic terms of the natural water surface evaporation model were corrected. Taking the evaporation of the water surface covered by spheres (coverage rate of spheres is 76.4%) as an example, based on the rose change characteristics of the above parameters, the effects of these modified evaporation models are comprehensively evaluated from three different time scales (even months, odd months and the complete test period). The evaluation methods include the root mean square error (RMSE), index of agreement (D), mean bias error (MBE), and coefficient of determination (R2). The results show that under three different time scales, the Penman-Monteith model is the most promising and superior in estimating water surface evaporation under floating coverage (for the complete test period, RMSE=0.11 mm·d−1, D=0.99, MBE= 0.07 mm·d−1, and R2 =0.99); the Priestley-Taylor model is slightly less effective in estimating evaporation than the Penman-Monteith model, and the mass transfer model and the Penman model are less effective in estimating evaporation. Furthermore, the analysis of the Penman-Monteith model shows that the evaporation of the radiation term (69.5%) is higher than that of the aerodynamic term (30.5%) during the evaporation of the water surface under floating coverage, while the evaporation of the radiation term is dominant. Moreover, during the complete test period, the weights of the radiation evaporation and aerodynamic evaporation changed significantly with time. The proportion of radiation evaporation varies from 54.8% to 81.7%, while that of aerodynamic evaporation varies from 18.3% to 45.2%.