Influence of MRE Education on Explosive Ordnance Disposal in Quang Tri

In collaboration with local and international organizations, Project RENEW is facilitating comprehensive mine risk education initiatives in Vietnam’s Quang Tri province

An Efficient Spectral Leakage Filtering for IEEE 802.11af in TV White Space

Orthogonal frequency division multiplexing (OFDM) has been widely adopted for modern wireless standards and become a key enabling technology for cognitive radios. However, one of its main drawbacks is significant spectral leakage due to the accumulation of multiple sinc-shaped subcarriers. In this paper, we present a novel pulse shaping scheme for efficient spectral leakage suppression in OFDM based physical layer of IEEE 802.11af standard. With conventional pulse shaping filters such as a raised-cosine filter, vestigial symmetry can be used to reduce spectral leakage very effectively. However, these pulse shaping filters require long guard interval, i.e., cyclic prefix in an OFDM system, to avoid inter-symbol interference (ISI), resulting in a loss of spectral efficiency. The proposed pulse shaping method based on asymmetric pulse shaping achieves better spectral leakage suppression and decreases ISI caused by filtering as compared to conventional pulse shaping filters

Upper bound limit analysis of plates using a rotation-free isogeometric approach

International audienceThis paper presents a simple and effective formulation based on a rotation-free isogeometric approach for the assessment of collapse limit loads of plastic thin plates in bending. The formulation relies on the kinematic (or upper bound) theorem and namely B-splines or non-uniform rational B-splines (NURBS), resulting in both exactly geometric representation and high-order approximations. Only one deflection variable (without rotational degrees of freedom) is used for each control point. This allows us to design the resulting optimization problem with a minimum size that is very useful to solve large-scale plate problems. The optimization formulation of limit analysis is transformed into the form of a second-order cone programming problem so that it can be solved using highly efficient interior-point solvers. Several numerical examples are given to demonstrate reliability and effectiveness of the present method in comparison with other published methods

The mathematical model of the improved system of the seat with adjustable pressure profile

Following a patented solution, a seat which is possible to change its stiffness was created. The seat contains an actively controlled pneumatic spring element (the PSE). For the requirement of working faster and more precisely, an improvement was applied. This article deals with derivation of mathematical model of the improved PSE system used for subsequent analysis. The model is considered as a mixed model which is a combination of single-discipline subsystems as mechanical, electrical, fluid and control ones. The simulations are carried out for varied input parameters and both the system parameters and system characteristics are calculated. The results describe the behavior of the improved system in two modes of controller setup: constant pressure and constant stiffness under static and dynamic condition

MORPHOLOGICAL AWARENESS OF STUDENTS MAJORING IN ENGLISH STUDIES TOWARDS VOCABULARY LEARNING

For those learning a second language, vocabulary plays a vital role in mastering the new one, and possessing a colossal vocabulary is extremely necessary. The paper aims to look into and assess students' awareness of morphology and the effectiveness of this approach through vocabulary learning. The subjects in this study were juniors majoring in English at a university in the south of Vietnam. The test, questionnaire, and interview were the three instruments used in this study to triangulate the results. A total of 49 students majoring in English Studies took the test, 40 students completed the questionnaire, and four students participated in an interview to evaluate their proficiency and morphological knowledge. The results of the study showed that students' awareness levels were average, and they were knowledgeable enough to employ this strategy for acquiring vocabulary. Additionally, it also enables students to comprehend morphology's benefits and drawbacks during their learning vocabulary process.  Article visualizations

Laboratory Hydro-mechanical Characterisation of Boom Clay at Essen and Mol

International audienceBoom clay has been selected as a potential host rock formation for the geological disposal of radioactive waste in Belgium. In the present work, the hydro-mechanical behaviour of Boom clay samples from the borehole Essen-1 at a depth of 220 - 260 m and from HADES that is the underground rock laboratory at Mol in Belgium, at 223-m depth was investigated in the laboratory by performing low pressure oedometer tests (vertical effective stress ranging from 0.05 to 3.2 MPa), high pressure oedometer tests (vertical effective stress ranging from 0.125 to 32 MPa), isotropic consolidation tests (confining effective stress ranging from the in-situ stress to 20 MPa) and triaxial shear tests. It has been observed that the mineralogy, geotechnical properties and hydro-mechanical behaviour of Boom clay from Essen at 227-m, 240-m and 248-m depths are similar to that of Boom clay from Mol. As in the case of Boom clay at Mol, the failure envelope of Boom clay at Essen in the p'-q plane is not linear. The slope of the portion beyond the pre-consolidation stress of Boom clay from Essen is almost the same as that from Mol, suggesting a similar internal friction angle of about 13°. The compression curves (void index Iv versus logarithm of vertical stress) beyond the pre-consolidation stress are the same for both samples from Mol and Essen, and situated between the intrinsic compression line (ICL) and the sedimentation compression line (SCL). The yield stress determined from oedometer tests seems to be stress-path dependent and lower than the pre-consolidation stress. Thus determining the over-consolidation ratio (OCR) using the yield stress value would lead to an incorrect estimate. From a practical point view, the laboratory test results from Essen and their comparison with those from Mol provide important information regarding the transferability of knowledge on Boom clay at different sites, taking into account the fact that most investigations have been carried out on Boom clay at Mol

Investigating the pore-water chemistry effects on the volume change behaviour of Boom clay

International audienceThe Essen site has been chosen as an alternative site for nuclear waste disposal in Belgium. The soil formation involved at this site is the same as at Mol site: Boom clay. However, owing to its geographical situation closer to the sea, Boom clay at Essen presents a pore water salinity 4-5 times higher than Boom clay at Mol. This study aims at studying the effects of pore water salinity on the hydro-mechanical behaviour of Boom clay. Specific oedometer cells were used allowing "flushing" the pore water in soil specimen by synthetic pore water or distilled water. The synthetic pore water used was prepared with the chemistry as that for the site water: 5.037 g/L for core Ess83 and 5.578 g/L for core Ess96. Mechanical loading was then carried out on the soil specimen after flushing. The results show that water salinity effect on the liquid limit is negligible. The saturation or pore water replacement under the in situ stress of 2.4 MPa does not induce significant volume change. For Ess83, hydro-mechanical behaviour was found to be slightly influenced by the water salinity; on the contrary, no obvious effect was identified on the hydro-mechanical behaviour of Ess96. This can be attributed to the higher smectite content in Ess83 than in Ess96

PHÁT HIỆN VI KHUẨN PASTEURELLA MULTOCIDA GÂY BỆNH TỤ HUYẾT TRÙNG Ở CỪU PHAN RANG BẰNG KỸ THUẬT PCR

Pasteurellosis is an infectious disease causing severe damage to livestock and poultry since it leads to animals’ death, including sheep of all ages. In this study, we developed a sensitive, specific and accurate PCR method for detecting P. multocida in Phan Rang sheep using FKMT1/RKMT1 primers targeted to the KMT1 gene of P. multocida. The PCR-based method was used to detect the KMT1 gene from 104 copies of the KMT1-bearing plasmid. The method’s specificity was demonstrated by the successful amplification of KMT1 from the mixture containing other DNA of Gram-negative bacteria, such as E. coli or M. haemolytica. In particular, with the present method, we successfully detected P. multocida with crude DNA obtained from P. multocida or nasal swabs of pasteurellosis-suspected sheep samples treated in a TE buffer containing 0.1% TritonX-100. This is the first report on using a PCR-based method for detecting P. multocida from Phan Rang sheep, and it can serve as the basis for an effective procedure to diagnose pasteurellosis in sheep.Tụ huyết trùng là một bệnh truyền nhiễm có thể gây thiệt hại nghiêm trọng cho chăn nuôi gia súc, gia cầm nếu không được chẩn đoán và điều trị kịp thời. Vì vậy, trong nghiên cứu này chúng tôi đã phát triển phương pháp PCR có độ nhạy, độ đặc hiệu và độ chính xác cao để phát hiện sự có mặt của vi khuẩn P. multocida, một trong những tác nhân gây bệnh tụ huyết trùng trên cừu Phan Rang. Gen KMT1 của vi khuẩn P. multocida được nhân lên bằng cặp mồi đặc hiệu FKMT1/RKMT1 ở nồng độ khoảng 104 bản sao của plasmid mang gen đích. Phản ứng PCR không bị ảnh hưởng khi có mặt DNA của một số vi khuẩn Gram âm khác như E. coli hay M. haemolytica. Đặc biệt, với phương pháp PCR, chúng tôi đã phát hiện sự có mặt của vi khuẩn P. multocida từ mẫu DNA thô thu được bằng xử lý mẫu vi khuẩn/mẫu dịch ngoáy mũi của cừu nghi nhiễm bệnh trong đệm TE chứa 0,1% TritonX-100 mà không cần tinh sạch DNA tổng số. Đây là nghiên cứu đầu tiên công bố một phương pháp xác định sự có mặt của P. multocida trên cừu Phan Rang và là cơ sở để xây dựng quy trình chẩn đoán hiệu quả nhằm góp phần kiểm soát bệnh tụ huyết trùng trên đối tượng này