The RAMPDOOR HYDRAULIC SYSTEM MODIFICATION OF ANOA PANZER COMBAT VEHICLE

Panzer Anoa 6x6 is a combat vehicle on tires where the first generation of it is made by PT Pindad (Persero). It can mobility, protection and carrying capacity. The ramp door on the Anoa 6x6 APC armored vehicle is driven by a hydraulic system to support the mobility of personnel when exiting or entering the vehicle. The components of the hydraulic system driving the Panzer Anoa 6x6 APC ram door include batteries, power packs, solenoid valves, hydraulic hoses, and hydraulic cylinders. These problems include the ramp door often not functioning, the ramp door moving too slowly and often experiencing congestion when the ramp door is working. These constraints often occur because the pump in the hydraulic system is driven by an electric motor that gets its power source from the battery. The fluid is pressed and flowed through a hydraulic pipe, then the flow of the pressurized fluid is regulated by a solenoid valve to the hydraulic cylinder to move the ramp door. This study uses a pure experimental quantitative method with empirical calculations to obtain a tool with the desired specifications. To move the ramp door weighing 200 kg with a maximum opening angle of 100 degrees in 8 seconds, the heaviest load received by the cylinder is 23557.44 N, the working pressure that occurs in the cylinder is 87.49 bar, where the fluid discharge will flow to the pump. of 2164.77 liters/minute, with a pump power of 394570 Watt and to continue the rotation of the engine with a rotation of 2814.13 rpm (idle) to the hydraulic pump using a pulley mechanism with a ratio of 1: 0.15.

Inter-Temporal Aggregation for Spatially Explicit Optimal Harvest Scheduling under Area Restrictions

We propose a new approach to solve inter-temporal unit aggregation issues under maximum opening size requirements using two models. The first model is based on Model I formulation with static harvest treatments for harvest activities. This model identifies periodic harvest activities using a set of constraints for inter-temporal aggregation. The second model is based on Model II formulation, which uses dynamic harvest treatments and incorporates periodic harvest activities directly into the model formulation. The proposed approach contributes to the literature on spatially constrained harvest scheduling problems as it allows a pattern of unit aggregation to change across multiple harvests over time, as inter-temporal aggregation under a maximum opening size requirement over period-specific duration. The main idea of the proposed approach for inter-temporal aggregation is to use a multiple layer scheme for a set of spatial constraints, which is adapted from a maximum flow specification in a spatial forest unit network and a sequential triangle connection to create fully connected feasible clusters. By dividing the planning horizon into period-specific durations for different spatial aggregation patterns, the models can complete inter-temporal spatial aggregation over the planning horizon under a maximum opening size requirement per duration. Study Implications Inter-temporal unit aggregation is important because it provides flexible aggregation patterns for maximum opening size problems with multiple harvests over time. We have proposed a new modeling approach capable of solving spatially constrained harvest scheduling problems by allowing a pattern of unit aggregation to change across multiple harvest periods over time, as inter-temporal aggregation under flexible maximum opening size requirements. Forest managers can benefit from this approach for their future requirements based on the public interests as well as their own.

Catastrophe Mechanism of Stress-Fissure Coupling Field in Mining Close Distance Seams in Southwest China

For the sake of studying the catastrophe mechanism of stress-fissure coupling field in mining close distance seams in southwest China, a test working face in Guizhou province in southwest China is adopted and researched by the methods of numerical calculation and similar experiment. When the working face advances to 180 m in 4# coal seam in a similar experiment, the overlying rock breaks to the central base plate of Yulongshan limestone, and the conductive fractures run through the Changxing limestone karst cave and Yulongshan limestone karst cave. When the 1402 working face advances to 350 m, the top of vertical karst caves in the middle of the model produces extrusion damage, forming a penetrating water inrush passage. When the 1402 working face advances to 480 m, the top slab of the working face comes under periodic weighting with the short step. Besides, the mining of 9# coal seam starts after 4# coal seam in mining close distance seams. When the working face in 9# coal seam advances to 340 m in numerical simulation, the maximum opening of the overburden fractures is 51.16 mm. The fractures in the roof are mainly caused by the periodic breaking and falling of the basic roof, connected with the floor fractures of 4# coal seam. When the working face in 9# coal seam advances to 500 m, the maximum opening of the overburden fracture is 93.09 mm. Specifically, as the working face advances, the opening of fracture in the roof after collapse of the basic roof periodically is mainly greater than 5 mm, and the compaction closure is mainly 1 mm-5 mm. The fractures in the gob floor are mainly 0.1 mm-1 mm, and the fracture opening of the collapsed rock mass in the gob is mainly 1 mm-5 mm and greater than 5 mm. The karst caves in the overburden reduce the periodic weighting step of working face and play a guiding role in the direction of fracture development and water inflow passage formation. The karst caves are connected to surface waterfall holes and trap pits, and atmospheric precipitation recharges the water in the caves. The research results can be treated as an important basis for the prevention and treatment for water inrush disaster in mining close distance seams in the karst area of southwest China.

Maximum Mouth Opening Range in Adult Patients Presented at Dental OPD CMH, Lahore

Objective: To determine the maximum mouth opening (MMO) in Pakistani adult population and its possible correlation with sex and age. Design of the Study: It was a cross-sectional study. Study Settings: This study was carried out at Outpatient Department of Dentistry Combined Military Hospital, Lahore from January 2019 to July 2019. Material and Methods: The study involved 894 adults’ patients having 463 males and 431 females patients age in the range of twenty one year to seventy years. The patients were asked maximally open their mouth and keep it open until no further opening of mouth possible. Then with the help of calibrated fiber ruler distance was measured from incisal edge of the upper incisor teeth to the incisal edge of the lower incisor teeth. To check the correlation of mouth opening with age a Pearson correlation analysis was done and significance of the test was checked by applying the independent sample T-test will be applied taking p value of ≤0.05 as statistically significant. A written informed consent was obtained from every patient. Results of the Study: For males mean maximum opening of mouth was observed as 51.4±8.1 mm having its range 38 to 70. Mean maximum opening of mouth for females was observed as 43.1±5.9 mm having age range 37 to 55 mm. In 21 to 30 years age group the opening of mouth was 39.90 ± 5.02 mm for female’s patients and 40.26 ± 5.26 mm for male patients. In 31 to 40 years age group the opening of mouth was 39.54 ± 4.69 mm for females and for female’s patients it was 40.24 ± 4.55 for male patients. In 41 to 50 years age group MMO was 40.24 ± 5.02 mm for females and was 40.97 ± 4.79 mm for males. In age 51 to 60 years age group the equivalent values for males were 41.54 ± 5.49 and for females41.04 ± 5.63 mm. In 61 to 70 years age group the corresponding values for females and males were 40.33 ±5.55 mm and41.25 ± 6.04 respectively. Conclusion: The mean MMO for males was 51.4 ± 8.2 and for females was 43.1 ± 6.7. The opening of the mouth looks to reduce with age. The opening of mouth of females is not as much of the males in the all groups of age. Keywords: Maximum mouth opening (MMO), Age, Sex

Characterization of Open-Cell Sponges via Magnetic Resonance and X-ray Tomography

The applications of polymeric sponges are varied, ranging from cleaning and filtration to medical applications. The specific properties of polymeric foams, such as pore size and connectivity, are dependent on their constituent materials and production methods. Nuclear magnetic resonance imaging (MRI) and X-ray micro-computed tomography (µCT) offer complementary information about the structure and properties of porous media. In this study, we employed MRI, in combination with µCT, to characterize the structure of polymeric open-cell foam, and to determine how it changes upon compression, µCT was used to identify the morphology of the pores within sponge plugs, extracted from polyurethane open-cell sponges. MRI T2 relaxation maps and bulk T2 relaxation times measurements were performed for 7° dH water contained within the same polyurethane foams used for µCT. Magnetic resonance and µCT measurements were conducted on both uncompressed and 60% compressed sponge plugs. Compression was achieved using a graduated sample holder with plunger. A relationship between the average T2 relaxation time and maximum opening was observed, where smaller maximum openings were found to have a shorter T2 relaxation times. It was also found that upon compression, the average maximum opening of pores decreased. Average pore size ranges of 375–632 ± 1 µm, for uncompressed plugs, and 301–473 ± 1 µm, for compressed plugs, were observed. By determining maximum opening values and T2 relaxation times, it was observed that the pore structure varies between sponges within the same production batch, as well as even with a single sponge.

Modelling multi-fissure zones above buried rock ridges in subsiding basins

<p>Aseismic earth fissures due to the excessive groundwater exploitation have caused seriously damage in many subsiding sedimentary basins worldwide. Generally, multiple fissures almost parallel to each other with equal distances are prone to develop where a compacting aquifer system overlies impermeable and/or incompressible ridges. Here, an advanced finite-element interface-elements modelling approach is employed to understand this process within unfaulted sedimentary sequences. A simplified geological setting is initially used to investigate the effect of the ridge slope on ruptures behaviors. Then, we reproduce the case of Guangming village, China. In both the proposed scenarios, the model simulates the occurrence of multi-fissures that initiate at land surface and propagate downward, as observed in the sites. The earth fissures are formed as a result of the combination of tensile stress (bending condition) and shear stress (shearing conditions) accumulation around and above the tip and the slopes of the ridge, respectively. The numerical outcomes indicate that the steeper ridge results in higher magnitude stress accumulation above the ridge tip which favors the formation of fissures with significant opening and small or null offset, but at expense of the reduction in stress accumulation area and fissure distribution. In Guangming case, the outcomes show that two ruptures started sliding and only one year later a central fissure opened and propagated down to 15-30 m depth. The simulated maximum opening and sliding of the central and side fissures, respectively, approximate 30 cm, which are almost in agreement with the observations. The numerical results prove that the proposed modeling approach is an effective way to predict and analyze multi-fissure onset and development in subsiding basins.</p>

QUANTIFYING WINDOW EFFECTIVENESS TO AFFECT WIND VELOCITY BY EXPERIMENTAL STUDY

Particular ventilation design can create effective natural air movement into the indoor environment by flowing the outside wind. The window, as a kind of ventilation, has various designs. It combines three primary constructions: simple opening, vertical-pivot, and horizontal-pivot opening. Each has a particular characteristic to control air velocity and direction which flows through it. However, the wind is not always certain in the mean of its velocity and direction, which heavily relies on the season. This study is written to investigate the single window’s performance by measuring its effectiveness to control wind velocity in some directions. The effectiveness is conceived as a percentage rate that a window could maintain the outside wind velocity when it flows through the window. This experimental study employs three factors that are wind direction, window design and opening angle. This study operated 1:1 model of ten window designs, a simulation wall, and an electric fan to generate the Building Physics Laboratory's intended wind in the Department of Architecture, Institut Teknologi Indonesia. The result shows that maximum opening angle with perpendicular wind is the most effective situation to flow wind through all window—except simple casement window—with the rate ranging at 85,16% – 123,76%. The wind could also be more speeded up 109,63% – 193,90% when it aligned to all windows. Simple casement window even reaches 266,22% when the wind perpendicular.

Comparative evaluation of soft and hard splints in treatment of clenching disorder

Introduction: The aim of this study was to compare the efficiency of soft and hard splints in treating patients with clenching. Materials and Methods: In this clinical study, 26 patients with clenching disorder random- ly divided to two equal group of treatment: hard and soft splint. The amount of masticatory muscle pain and maximum mouth opening were measured at the delivery time and 3, 6, 9, and 12 weeks later by a blind examiner. Data were analyzed by independent T and repeated measure ANOVA tests with significance level of p=0.05. Results: Hard and soft splints were resulted in significant reduction of masticatory muscle pain (hard: P<0.001, Soft: p<0.001) and increase in maximum opening (hard P<0.001, Soft p<0.003), but there was no significant difference between them in pain relieving (P=0.848) and maximum opening (P=0.622). Conclusion: This study showed that efficacy of hard and soft splints in treating patients with clenching is same.

Avaliação funcional após uso de placa oclusal em pacientes com disfuncão temporomandibular

This study aimed to evaluate the amplitude and pattern of mouth opening in patients treated with occlusal plaque (OP) after 1 and 3 months of treatment. The mouth opening pattern was assessed using the metric method and the mouth opening amplitude of 23 patients treated with occlusal plaque (OP; N = 23). All patients were diagnosed with TMD according to axis 1 of the RDC/TMD (Research Diagnostic Criteria for Temporomandibular Disorders). The collected data were evaluated using the SPSS program using the Wilcoxon, Kruskal Wallis, and Fisher’s exact Chi Square tests. The OP showed a satisfactory performance in the opening pattern variable, maintaining the same pattern as the patient throughout the treatment time (P = 0.003). In the variable of maximum opening amplitude, the therapy showed a significant improvement in amplitude gain in the initial time and after one month of therapy (P = 0.002), maintaining the amplitude until the third month, without presenting significant gain. It was concluded that OP has a satisfactory performance for the treatment of TMD when the opening pattern and the mean maximum opening amplitude are analyzed without assistance.

Adaptability of the Cutter-Head of the Earth Pressure Balance (EPB) Shield Machine in Water-Rich Sandy and Cobble Strata: A Case Study

Earth Pressure Balance (EPB) shield machines are considered to be the most efficient tunneling method for Metro tunnels due to their adaptability to a great variety of ground conditions, higher construction efficiency, and providing a safer working environment. There are many guidelines available for EPB shield machine selection. However, these guidelines are very general and cannot be used directly for an upcoming project. This paper takes Chengdu Metro Line 6 in China as the engineering background; the studied area is typical of a water-rich sandy and cobble stratum with high content of cobble. Three types of EPBs in the two continuous intervals exhibit significant differences in performance and encounter many difficulties such as wear of the cutter disc and tools, clogging, and severe surface settlement during the operation. These difficulties prevent the construction efficiency, increase the cost of the project, and cause delays in construction period. The causes of these difficulties are summarized by recording and comparing the operational parameters of the three types of EPBs. These parameters that are summarized include the advance rate, total thrust, torque, and the rate of rotation of the cutter-head. In addition, the surface settlements are also compared. The results indicate that the opening rate, maximum opening size, and the opening position of the cutter-head are key factors that affected the geological adaptability of the shield machine in water-rich sandy and cobble strata. Among the three factors, the maximum opening size and opening position are the most important factors influencing the strata adaptability of the cutter-head. To avoid frequent jams of the cutter-head, the maximum torque should be not less than 6,500 kNm. The maximum opening size should not be less than 420 mm × 420 mm. The effect of increasing the central opening of the cutter-head is that large cobbles and boulders can be discharged through the central opening when they cannot be discharged through the opening near the original position of the cobbles and boulders. This paper provides specific guidance on the selection of cutter-head for shield machines in water-rich sandy and cobble strata.