A model for determining the time of pointing a grip-cutting device of feller buncher machines on a growing tree

Исследование посвящено нахождению аналитической математической модели по определению времени наведения захватно-срезающего устройства на растущее дерево. В качестве известных параметров используются конструктивные размеры технологического оборудования, снятые с компоновочно-кинематических схем валочно-пакетирующих машин, требуемая высота пня и среднее расстояние между деревьями пасики. Поиск требуемой модели кратко можно разделить на несколько последовательных этапов: нахождение пути, который пройдет шток гидроцилиндра привода стрелы, и по известной формуле скорости перемещения поршня гидроцилиндра находится время на подвод стрелы к дереву; нахождение пути, который пройдет шток гидроцилиндра привода рукояти; нахождение пути, который пройдет шток гидроцилиндра привода наклона захватно-срезающего устройства; нахождение пути, который пройдет шток гидроцилиндра привода рычагов захвата в процессе раскрытия. Сумма времени на подвод каждого из элементов технологического оборудования и есть время на наведение, присущее неопытному оператору, в случае опытного оператора время на наведение захватно-срезающего устройства к дереву определяется максимальным временем одного из компонентов. The research is devoted to finding an analytical mathematical model for determining the aiming time of a feller head on a growing tree. As the known parameters are used. The design dimensions of the technological equipment, taken from layout and kinematic diagrams of feller-buncher machines, the required stump height and the average distance between the trees of the windrow. The search for the required model can be briefly divided into several successive steps: finding the path that the hydraulic cylinder rod of the boom drive will take and by the known formula of speed of movement of the hydraulic cylinder piston is time to bring the boom to the tree; finding the way which the rod of the hydraulic cylinder of the arm drive; to find the path which the hydraulic cylinder rod of the tilt of the feller head; finding the path which the hydraulic cylinder rod for the arm actuator will take during the opening. The sum of the time for supplying each of the elements of technological equipment is the time required for the orientation, which is characteristic for a nonexperienced operator. In case of an experienced operator the time for setting the feller head to the tree is determined by the maximum time of one of the components.

COMPARATIVE ASSESSMENT OF DIFFERENT DIAGNOSTIC TECHNIQUES IN THE IDENTIFICATION OF MYCOBACTERIUM TUBERCULOSIS IN SUSPECTED CASES OF TUBERCULOSIS

Statement of the Problem: Tuberculosis remains a serious public-health threat in developing countries though it has been eradicated in some advanced countries. This disease constitutes a significant threat to global health, being the second highest cause of morbidity and mortality resulting from infectious agents. Prompt diagnosis of active TB facilitates timely therapeutic intervention and minimizes community transmission. Aim: This study aimed at determining a ‘Point of Care’ diagnostic tool for pulmonary tuberculosis (PTB) by comparing the efficiency of four different PTB diagnostic tools for different age groups. Methodology: Zeihl Nelson (ZN) staining, culture, Gene xpert (GX) and Lipoarabinomanan (LAM) assay were employed in this study The culture method was used for confirmation. Sputum and urine samples were collected from each of 100 patients symptomatically diagnosed of PTB. Findings: Fifty-seven percent of the population was male while 43% were female. Mycobacterium tuberculosis was isolated from 9 (9%) of 100 patients. Similarly, GX detected Mycobacterium tuberculosis in 9 (9%) of the patients while the rate of detection using LAM was 10% and with ZN it was 7%. Gene xpert produced no true or false positive and negative result, LAM had one false positive result and ZN had two false negative results. The maximum time frame to generate result was 25 minutes for LAM, two hours for Gene xpert, eight weeks for culture and two days for ZN. Two positive isolates were observed at the same frequency for age group 21-30 and 31- 40 while age groups 1-10, 10-20, 41-50, 50-60 and above has 1 positive result each. Gene xpert had 98.11% sensitivity while LAM had 96.23% and ZN had 86.79%. The choice of ‘Point of Care’ diagnostic tool is of great concern to clinicians and the general public. Conclusion & Significance: This study identified LAM assay as suitable ‘Point of Care’ diagnostic and an add-on tool for PTB diagnosis because of its relatively high sensitivity and short maximum time frame to generate result compare to other three diagnostic techniques.

Adaptability Mechanisms of Japonica Rice Based on the Comparative Temperature Conditions of Harbin and Qiqihar, Heilongjiang Province of Northeast China

Japonica rice has been considerably impacted from climate change, mainly regarding temperature variations. Adjusting the crop management practices based on the assessment of adaptability mechanisms to take full advantage of climate resources during the growing season is an important technique for japonica rice adaptation to climate changed conditions. Research based on the adaptability mechanisms of japonica rice to temperature and other environmental variables has theoretical and practical significance to constitute a theoretical foundation for sustainable japonica rice production system. A contrived study was arranged with method of replacing time with space having four different japonica cultivars namely Longdao-18, Longdao-21, Longjing-21, and Suijing-18, and carried out in Harbin and Qiqihar during the years 2017–2019 to confer with the adaptability mechanisms in terms of growth, yield and quality. The formation of the grain-filling material for superior and inferior grains was mainly in the middle phase which shared nearly 60% of whole grain-filling process. Maximum yield was noticed in Longdao-18 at Harbin and Qiqihar which was 9500 and 13,250 kg/ha, respectively. The yield contributing components fertile tillers, number of grains per panicle, and 1000-grain weight were higher at Qiqihar; therefore, there was more potential to get higher yield. The data for grain-filling components demonstrated that the filling intensity and duration at Qiqihar was contributive to increase the grain yield, whereas the limiting agents to limit yield at Harbin were the dry weights of inferior grains. The varietal differences in duration and time of day of anthesis were small. Across all cultivars and both study sites, nearly 85% of the variation of the maximum time of anthesis could be justified with mean atmospheric temperature especially mean minimum temperature. Mean onset of anthesis was earliest in Longdao-21 at Harbin, whereas it was latest in Longdao-18 at Qiqihar. The maximum time to end anthesis and the longest duration of anthesis were taken by Longdao-18, i.e., 9.0 hasr and 4.2 h, respectively. Chalkiness and brown rice percentages were elevated at Qiqihar showing Harbin produced good quality rice. This study investigated the adaptability mechanisms of japonica rice under varying temperature conditions to distinguish the stress tolerance features for future sustainability and profitability in NEC. It was concluded that there is an adaptive value for anthesis especially regarding Tmin and, moreover, earlier transplantation may produce tall plants. The results demonstrated that high temperature at the onset of anthesis at the start of the day enhanced the escape from high temperature later during the day. Early transplantation is recommended in NEC because earlier anthesis during humid days rendered for potential escape from high ambient temperature later during that day. Temperature influenced japonica rice significantly and coherently, whereas the influence of growing season precipitation was not significant. Daily mean sunshine influenced the japonica rice significantly, but the impact was less spatially coherent. The results foregrounded the response of the japonica rice to external driving factors focusing climate, but ignored socioeconomic suggesting emphasis on both driving factors to target future research and render important insights into how japonica rice can adapt in mid-high-latitude regions.

Joint Medicines Regulatory Procedure in the East African Community: Registration Timelines and Way Forward

A review of the East African Community (EAC) joint regulatory review process was conducted, registration timelines analyzed and key milestones, challenges and opportunities documented for the period of July 2015 to January 2020. A total of 113 applications were submitted for joint scientific review. Among these, 109 applications were assessed, 57 were recommended for marketing authorisation, 52 applications had queries to applicants and four applications were under review. A total median approval time for all products ranged from 53 to 102 days. The maximum time taken by a regulator to review the dossier was 391 days and the minimum time was 44 days. For applicants, the maximum time to respond to queries was 927 days and the minimum time was nine days. The total median time for granting marketing authorisation by the National Medicines Regulatory Authorities (NMRA) decreased from 174 to 39 working days in 2015 and 2019 respectively. However, not all EAC NMRA has granted marketing authorisation to all 57 products due to non-payment of applicable fees by applicants. Long regulatory approval timelines were contributed by limited capacity for timely scientific review of dossier by some NMRA, lack of online portal to share dossiersand assessment reports, delay in responding to queries by applicants and deficiencies in dossier. The metric tool and register of medical products submitted for joint scientific review had incomplete data. Challenges were identified and actions recommended to ensure regional regulatory system optimization, efficiency, transparency, sustainability and accountability.

Resolution-intensity optimisation on quasielastic neutron scattering spectrometers

In quasieleastic neutron scattering spectrometers one usually faces a trade-off between energy resolution and counting statistics. If the resolution is improved the intensity at the detectors reduces and vice versa. It is not immediately clear how to weigh both factors against each other. In this paper it is proposed to use the maximum time obtainable by Fourier transform of the spectra as the quantity to be optimised. It is shown that this leads to a well-defined criterion for the choice of the resolution.

Minimax model of transport operations of emergency on-orbit servicing in heliosynchronous orbits

Heliosynchronous orbits are attractive for space system construction. As a result, the number of spacecraft operating therein is constantly increasing. To increase their efficiency, timely on-orbit servicing (both scheduled and emergency) is needed. Emergency on-orbit servicing of spacecraft is needed in the case of unforeseen, emergency situations with them. According to available statistical estimates, emergency situations with serviced spacecraft are not frequent. Because of this, serviced spacecraft must be within the reach of a service spacecraft for a long time. In planning emergency on-orbit servicing, the following limitations must be met: the time it takes the service spacecraft to approach any of the serviced spacecraft must not exceed its allowable value, and the service spacecraft’s allowable energy consumption must not be exceeded. This paper addresses the problem of searching for emergency on-orbit servicing that would be allowable in terms of time and energy limitations and would meet technical and economical constraints. The aim of this work is to develop a mathematical constrained optimization model for phasing orbit parameter choice, whose use would allow one to minimize the maximum time of transport operations in emergency on-orbit servicing of a spacecraft group in the region of heliosynchronous orbits. The problem is solved by constrained minimax optimization. What is new is the formulation of a minimax (guaranteeing) criterion for choosing phasing orbit parameters that minimize the maximum time of emergency on-orbit servicing transport operations. In the minimax approach, the problem is formulated as the problem of searching for the best solution such that the result is certain to be attained for any allowable sets of indeterminate factors. The proposed mathematical model may be used in planning emergency on-orbit service operations to minimize the maximum duration of emergency on-orbit servicing transport operations due to a special choice of the service spacecraft phasing and parking orbit parameters.

Effects of face mask use on exercise during the covid-19 pandemic: the principal component analysis (PCA)

The COVID-19 pandemic also raised questions about the practice of physical activity using a face mask and how this would affect breathing and performance. The aim of this study was to investigate the effects of using a tissue face mask recommended by the World Health Organization (WHO) on the variation of heart rate (HR), minute volume (VE), and muscle O 2 saturation (SO 2 m) parameters during performing the incremental load exercise and verifying the maximum time obtained at the end of the exercise. A 21-year-old male, 85 kg of total body mass and 1.68 m of height were selected. The individual performed an incremental load test to maximum exhaustion on the XT cycle ergometer (TRG Fitness ®️ ) in two moments: No mask -Control (C); Cloth Mask (CM). The individual was instructed to maintain a cadence of 61-65 rpm and every 2 minutes a load of 30.8 watts was added until maximum exhaustion. A ventilometer VO2 Pro (Cefise ®️ ) and a near infrared spectroscopy sensor (Moxy ®️ ) were used, placed in the vastus lateralis muscle of the right leg.Data were analyzed every 20% of the total time (20%, 40%, 60%, 80% and 100%) under conditions C and CM. The parameters of HR, VE and SO 2 m were monitored throughout the test and the data were statistically processed by a software (Origin Pro ®️ 3.226) using a multivariate analysis technique (Principal Component Analysis -PCA) to analyze interrelationships between the variables. In test condition C, an eigenvalue of 2.979 was observed with two variables (VE and SO 2 m) associated with greater variation (PC1). The maximum time obtained at the end of the test was 1535 seconds. In the CM condition, na eigenvalue of 2.881 was observed with two variables (HR and SO 2 m) associated with greater variation (PC1). The maximum time obtained at the end of the test was1330 seconds. It is concluded that the use of CM reduces VE variation, which may be associated with greater airflow resistance. The greatest variation observed in HR was due to the use of CM, impacting the delay in the appearance of the plateau. In addition, the use of a tissue mask recommended by the WHO reduces the maximum exercise time performed on the cycle ergometer in a healthy individual. These findings are useful for evaluating the effects of using CM in high-performance sports. Additional studies in the elderly and people with lung or heart disease are needed.

EXTENSION OF THE MINIMUM COST FLOW PROBLEM (MCFP OR CNF) BY CONSIDERATION OF TIME AND QUANTITY OF LOADS WITH MAXIMUM TIME

This paper extends the general problem of minimizing the total cost of transport on the road network (CNF) by considering the total time, maximum time and total amount of cargo with the longest time. In the literature available to us, models with timing and amount of cargo in the case of a standard transport task were exposed. Optimization is possible by combining 5 criteria, 2 linear and 3 nonlinear ones over the same set of linear constraints. Multicriteria optimization determines Pareto-optimal solutions. Interactive analyst-software algorithms for solving the selected models were defined. The solution of hypothetical problems was illustrated. Closed model with 5 two-way asymmetric communications using software for CNF and it is possible to use software for LP. Four one-criteria problems were solved: total costs, overall transport performance from a time standpoint, transport time (problem of the second type by time) total transport time (problem of the third type by time) and one bi-criteria problem related to the simultaneous minimization of the maximum duration of transport and total costs.

Stability analysis of implicit semi-Lagrangian methods for numerical solution of non-hydrostatic atmospheric dynamics equations

The stability of implicit semi-Lagrangian schemes for time-integration of the non-hydrostatic atmosphere dynamics equations is analyzed in the present paper. The main reason for the instability of the considered class of schemes is the semi-Lagrangian advection of stratified thermodynamic variables coupled to the fixed point iteration method used to solve the implicit in time upstream trajectory computation problem. We identify two types of unstable modes and obtain stability conditions in terms of the scheme parameters. Stabilization of sound modes requires the use of a pressure reference profile and time off-centering. Gravity waves are stable only for an even number of fixed point method iterations. The maximum time step is determined by inverse buoyancy frequency in the case when the reference profile of the potential temperature is not used. Generally, applying time off-centering and reference profile to pressure variable is necessary for stability. Using reference profile for potential temperature and an even number of the iterations allows one to significantly increase the maximum time-step value.