Segregation Index—A New Soil Parameter for Internal Erosion Assessment

Internal erosion is a major cause related to nearly half of dam dysfunctions and failures. This phenomenon occurs when loose soil particles are transported outwards the soil mass by seepage through a series of pores and pore constrictions. As loose particles are usually fine and embedded in the pores formed by the soil primary fabric, traditional methods often correlate the representative sizes of fine and coarse particles to indicate the susceptibility to internal erosion of an assessed soil. These methods are not very accurate because soil particle size distribution can vary widely with several identical key sizes. This paper presents a new indicator for internal erosion assessment using the probability to be transported of loose particles: the segregation index. This index is estimated experimentally and analytically for the correlation with internal erosion test results. The index also has a significant role in the estimation of real effective stress of soils

An efficient approach to measure the difficulty degree of practical programming exercises based on student performances

oai:ojs.www.rev-jec.org:article/282This study examines the generality of easy to hard practice questions in programming subjects. One of the most important contributions is to propose four new formulas for determining the difficulty degree of questions. These formulas aim to describe different aspects of difficulty degree from the learner's perspective instead of the instructor's subjective opinions. Then, we used clustering technique to group the questions into three easy, medium and difficult degrees. The results will be the baseline to consider the generality of the exercise sets according to each topic. The proposed solution is then tested on the data set that includes the results of the two subjects: Programming Fundamentals, Data Structures and Algorithms from Ho Chi Minh City University of Technology. The most important result is to suggest the instructors complete various degrees according to each topic for better evaluating student's performance

Microfluidic Chip for Trapping Magnetic Nanoparticles and Heating in Terms of Biological Analysis

In this study, we reported the results of the design and the fabrication a planar coil in copper (square, a = 10 mm, 15mm high, 90 turns), these planar coils were integrated in a microfluidic chip for trapping magnetic nanoparticles and local heating applications. A small thermocouple (type K, 1 mm tip size) was put directly on top of the micro-channel in poly(dimethyl-siloxane) in order to measure the temperature inside the channel during applying current. The design of planar coils was based on optimizing the results of the magnetic calculation. The most suitable value of the magnetic field generated by the coil was calculated by ANSYS® software corresponded to the different distances from the coil surface to the micro-channel bottom (magnetic field strength Hmax = 825 A/m). The magnetic filed and heating relationship was balanced in order to manipulating the trapping magnetic nanoparticles and heating process. This design of the microfluidic chip can be used to develop a complex microfluidic chip using magnetic nanoparticles

GR-384 Benchmarking Network Service Performance Using the POWDER Wireless Testbed

5G RAN slicing provides a way to split network infrastructure into self-contained slices which can have various virtual network functions (VNFs) mapped onto them. Much work has gone into creating robust mapping and resource allocation algorithms in order to efficiently embed VNFs onto the available nodes in a slice. However, in order to most efficiently embed these VNFs we need to understand the resource and bandwidth needs of the services we are trying to embed. This project seeks to provide an accurate assessment of the needs of three commonly used network services. We do this by testing each network service using real world physical machines on the POWDER network testbed. We collect bandwidth and CPU usage data from each test and use it to analyze the needs of the network service when being embedded onto physical nodes during network slicing

A new record of congrid eel, Bathycongrus bleekeri (Congridae) from Vietnam

Three specimens of Bathycongrus bleekeri were collected during the survey in 2015 and 2017. The newly recorded species is described herein, a small, moderately elongate species of Bathycongrus with head and body compressed; vertical fins without black mark; tail slender, attenuated, but not filiform; trunk length 1.2 times greater than head length; teeth small, conical, in about three-four rows on jaws, in a small triangular patch on vomer; 28–29 preanal vertebrae, total of 111–113 vertebrae; 26–28 preanal lateral-line pores. Additional data on the morphology and distribution of the species increases the total number of known species in the family Congridae in Vietnamese waters to twelve

Influence of Structure on Optical Properties of WO3 Thin Films Deposited by Sputtering Method

In this paper we report the synthesis of WO$_{3}$ thin films and investigate the effect of the structure on their optical properties. The WO$_{3}$ thin films are coated on glass substrates from both W and WO$_{3}$ targets by the magnetron sputtering method in (Ar+O$_{2}$) plasma under different deposition temperatures, varying from room temperature to 480 \rc{}C. We also evaluate the band gap energy of WO$_{3}$ by considering the transitions between the valence and the conduction bands. This result suggests that the best choices are diagonal and allowed transitions. Based on the values of band gap energy and XRD pattern, we indicate the relationship between crystalline order and optical property and consequently, the difference in color of the samples

Female Germline Stem Cells: A Source for Applications in Reproductive and Regenerative Medicine

One of the most significant findings in stem cell biology is the establishment of female germline stem cells (FGSCs) in the early 21st century. Besides the massive contribution of FGSCs to support ovarian function and fertility of females, the ability to create transgenic animals from FGSCs have high efficiency. Whether FGSCs can differentiate into mature oocytes for fertilization and complete embryonic development is a significant question for scientists. FGSCs were shown to produce oocytes, and the fertilized oocytes could generate offspring in mice and rats. This discovery has opened a new direction in human FGSCs research. Recently, cryopreservation of ovarian cortical tissue was already developed for women with cancer. Thus, isolation and expansion of FGSCs from this tissue before or after cryopreservation may be helpful for clinical fertility therapies. Scientists have suggested that the ability to produce transgenic animals using FGSCs would be a great tool for biological reproduction. Research on FGSCs opened a new direction in reproductive biotechnology to treat infertility and produce biological drugs supported in pre-menopausal syndrome in women. The applicability of FGSCs is enormous in the basic science of stem cell models for studying the development and maturation of oocytes, especially applications in treating human disease

CÁ MÚ GIỐNG VÀ BẢO VỆ BÃI GIỐNG Ở ĐẦM THỊ NẠI, VỊNH QUY NHƠN VÀ ĐẦM CÙ MÔNG

The wild grouper fingerling have provided the important seed source for the development of commercial fish farming. Among the wild grouper fingerling collected in the Thi Nai lagoon, Quy Nhon bay (Binh Dinh) and Cu Mong lagoon (Phu Yen), 7 species of grouper have been identified as Banded grouper (Epinephelus amblycephalus), Yellow grouper (E. awoara), Longtooth grouper (E. bruneus), Malabar grouper (E. malabaricus), Sixbar grouper (E. sexfasciatus), Orange-spotted grouper (E. coioides) and grouper (Epinephelus sp.); in which three species of Longtooth grouper, Malabar grouper and Orange-spotted grouper were endangered in Red List Categories Criteria of IUCN as VU and NT. The Malabar grouper seed makes up a high proportion of over 30%. The total length of the juveniles is different between species, ranging from an average of 25.0 mm to 116.82 mm; Orange-spotted grouper is 112.48 mm in total length; four grouper species Banded grouper, Yellow grouper, Longtooth grouper and Malabar grouper are longer than 30 mm in total length with 31.96, 32.23, 33.78 and 33.86 mm respectively. The Sixbar grouper and grouper (Epinephelus sp.) are smaller than 30 mm. The catching of grouper fingerling is distributed in wide area, along the bank, mangroves in the lagoon, along the western shore of the Quy Nhon bay, from Ghenh Rang to the southern part of the coast and along the Cu Mong lagoon (from south to southwest). The production of grouper seed fluctuates irregularly, 3 - 4 million seeds per year for highest yields, alternating with very low yields. The protection of nursing grounds is necessary with the solution of selective catching and limiting artisanal fishing.Cá mú giống khai thác tự nhiên đã cung cấp nguồn giống quan trọng cho việc phát triển nuôi cá thương phẩm. Nguồn cá mú giống khai thác tự nhiên ở vùng đầm Thị Nại, vịnh Quy Nhơn (Bình Định) và đầm Cù Mông (Phú Yên) đã xác định được 7 loài là cá mú chấm vạch (Epinephelus amblycephalus), cá song gio (E. awoara), cá song nâu (E. bruneus), cá mú điểm gai (E. malabaricus), cá mú sau sọc (E. sexfasciatus), cá mú mè (E. coioides) và cá song (Epinephelus sp); trong đó có ba loài là cá song nâu (E. bruneus), cá mú điểm gai (E. malabaricus) và cá mú mè (E. coioides) là những loài được IUCN xếp ở mức nguy cấp bậc VU và NT. Con giống cá mú điểm gai chiếm tỉ lệ khá cao trên 30%. Chiều dài toàn thân trung bình cá giống của các loài khác nhau, từ 25,0 - 116,82 mm; cá mú mè  có chiều dài toàn thân lớn nhất đếm 112,48 mm, ba loài cá mú chấm vạch, cá song gio và cá mú điểm gai có chiều dài lớn hơn 30 mm tưong ứng là 31,96; 32,23; 33,78 và 33,86 mm. Hai loài còn lại là cá mú sáu sọc và cá song đều có kích thước nhỏ hơn 30 mm. Vùng khai thác cá mú giống khá rộng; dọc theo các cồn, dãi cây ngập mặn trong đầm Thị Nại, ven bờ phía bắc lên phía tây của vịnh Quy Nhơn; nơi tập trung khai thác ở ven gần bờ phía tây vịnh, từ Ghềnh Ráng kéo dài vào đến khu vực phía nam và vùng dọc bờ của đầm Cù Mông (từ phía nam đến tây nam). Sản lượng khai thác các mú giống biến động khá thất thường, năm có sản lượng cao lên đến 3 - 4 triệu con/năm, xen kẽ có năm sản lượng rất thấp. Việc bảo vệ bãi giống là cần thiết với các giải pháp khai thác có chọn lọc và hạn chế khai thác tận thu