Engineering Physical Factor Considerations for Specifying Dam Type During Memve’ele Dam Construction (South-Cameroon).

2021 ◽  
Author(s):  
sylvestre martial NTOMBA ◽  
Dieudonné Bisso ◽  
Lise Okomo Atouba ◽  
Rufine christelle Magnekou Takamte ◽  
Sylvie Durande Djikam Patipe ◽  
...  
Keyword(s):  
Construction Material ◽  
Concrete Structures ◽  
Construction Materials ◽  
Physical Factor ◽  
Earth Dam ◽  
Physical Factors ◽  
Dam Site ◽  
Geological Map ◽  
Selection Of ◽  
Dry And Rainy Seasons

Abstract This paper presents the results of engineering investigations used to select a best design for the Memve’ele dam. The selection of Memve’ele dam type has been based on consideration of physical factors such as topography, climate, availability of construction material, geology, geotechnical and foundation conditions and the selection of optima alternative between three dam types. According to these factors, Memve’ele valley is very wide and situated in the warm climate zone with dry and rainy seasons favorable to embankment type dam; the geology reveals very good conditions with Ntem formations and residual deposits as foundation materials and the dam site is not influenced by earthquake; this behavior is confirmed by geotechnical data and further indicates that this site is favorable to a composite dam type (embankment and concrete dams or connecting concrete structures) and the construction materials found within or near the dam site are suitable for usage. These characteristics have contributed retaining three dam types. The alternative of these three dams is a composite dam type option including homogeneous earth dam and rock fill dam with central core link by concrete structures. Engineering geological map and general layout of Memve’ele’s dam highlight the important role plays by engineers. The main dam that is observed actually in the Memve’ele dam site is composed from left to right of left connecting dam section, flushing sluice, main spillway section, riverbed dam section, auxiliary spillway section and right bank dam section.

STUDI BIONOMIK VEKTOR MALARIA DI KECAMATAN KALIBAWANG, KULONPROGO

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Sardjito Eko Windarso dkk
Keyword(s):  
Land Use ◽  
Malaria Vector ◽  
Rainy Season ◽  
Dry Season ◽  
Physical Factors ◽  
Mosquito Vector ◽  
Anopheles Species ◽  
Commercial Farming ◽  
Study Results ◽  
Dry And Rainy Seasons

The increasing of malaria cases in recent years at Kecamatan Kalibawang has been suspected correspond with the conversion of farming land-use which initiated in 1993. Four years after the natural vegetation in this area were changed become cocoa and coffee commercial farming estates, the number of malaria cases in 1997 rose more than six times, and in 2000 it reached 6085. This study were aimed to observe whether there were any differences in density and diversity of Anopheles as malaria vector between the cocoa and mix farming during dry and rainy seasons. The results of the study are useful for considering the appropriate methods, times and places for mosquito vector controlling. The study activities comprised of collecting Anopheles as well as identifying the species to determine the density and diversity of the malaria vector. Both activities were held four weeks in dry season and four weeks in rainy season. The mea-surement of physical factors such as temperature, humidity and rainfall were also conducted to support the study results. Four dusuns which meet the criteria and had the highest malaria cases were selected as study location. Descriptively, the results shows that the number of collected Anopheles in cocoa farming were higher compared with those in mix horticultural farming; and the number of Anopheles species identifi ed in cocoa farming were also more varied than those in the mix horticultural farming.Key words: bionomik vektor malaria, anopheles,

scholarly journals Evaluation of the Possibility of Using 1.4462 and 1.4501 Steel as a Construction Material for Apparatus Operating at an Increased Temperature and with Corrosive Factors

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4014
Author(s):  
Karol Prałat ◽  
Andżelika Krupińska ◽  
Marek Ochowiak ◽  
Sylwia Włodarczak ◽  
Magdalena Matuszak ◽  
...  
Keyword(s):  
Construction Material ◽  
Construction Materials ◽  
Optical Microscope ◽  
Passive Layer ◽  
Initial State ◽  
Time Intervals ◽  
Significant Deterioration ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Steel Heat

The objective of this study was to determine the requirements for steels used as construction materials for chemical apparatus operating at an elevated temperature and to correlate them with the properties of the tested steels. The experimental part examined the influence of the annealing process on the structure and properties of X2CrNiMoN22-5-3 (1.4462) and X2CrNiMoCuWN25-7-4 (1.4501) steel. Heat treatment was carried out on the tested samples at a temperature of 600 °C and 800 °C. Changes were observed after the indicated time intervals of 250 and 500 h. In order to determine the differences between the initial state and after individual annealing stages, metallographic specimens were performed, the structure was analyzed using an optical microscope and the micro-hardness was measured using the Vickers method. Potentiostatic tests of the samples were carried out to assess the influence of thermal process parameters on the electrochemical properties of the passive layer. An increase in the hardness of the samples was observed with increasing temperature and annealing time, the disappearance of magnetic properties for both samples after annealing at the temperature of 800 °C, as well as a significant deterioration in corrosion resistance in the case of treatment at a higher temperature.

Evaluation of a permissible roadbed thawing depth in permafrost

2021 ◽  
Vol 5 ◽  
pp. 18-22
Author(s):  
Alexandr Galkin
Keyword(s):  
Thermal Resistance ◽  
Biot Number ◽  
Seasonal Changes ◽  
Construction Materials ◽  
Thermal Conditions ◽  
Road Base ◽  
Thawing Depth ◽  
Roadway Construction ◽  
Selection Of ◽  
Purpose Of Evaluation

Roadbed thermal conditions in permafrost are subject to seasonal changes affecting roadway resilience. A roadbed thawing depth is important for road base processing, especially in permafrost. This research had the purpose of evaluation of a permissible roadbed thawing depth based on the Biot number reflecting general thermal resistance of roadbed layers. These results will contribute to understanding road bed thermal resistance and selection of roadway construction materials.

EFFECT OF YELLOW LOESS ON ODOROUS GAS ADSORPTION AND ECOTOXICITY TEST USING DAPHNIA MAGNA

2021 ◽  
Vol 16 (1) ◽  
pp. 103-114
Author(s):  
Hongseok Jang ◽  
Boram Lee ◽  
Seungyoung So
Keyword(s):  
Daphnia Magna ◽  
Cement Mortar ◽  
Construction Material ◽  
Objective Assessment ◽  
Test Chamber ◽  
Construction Materials ◽  
Ecotoxicity Test ◽  
Lamellar Crystal ◽  
Exposure Test ◽  
Natural Materials

ABSTRACT To minimize damage caused by harmful substances released from artificial construction materials, there has been increasing interest in eco-friendly houses constructed with natural materials. Among natural materials, yellow loess is South Korea’s most representative eco-friendly construction material, with high purification performance for indoor use. However, there has been no objective assessment of yellow loess’s performance at purifying indoor air. In this study, internal pores were found in yellow loess that were of a lamellar crystal structure consisting of bonds of silica and alumina plates, and there was a high negative charge on the loess surface; these might have contributed to the excellent performance of yellow loess in adsorbing odorous gas. There was also an exposure test using Daphnia magna to determine the eco-friendliness of yellow loess compared with that of cement mortar. Results showed the survival of Daphnia magna was longer in the indoor environment of a test chamber with higher concentration of ammonia wherein yellow loess was placed. EC50 (median effective concentration, the concentration that caused death of 50% of bio-specimens) value of 19 ml of ammonia (0.1% solution), which was three times more than EC50 value of 6 ml of ammonia of the same area of cement mortar.

Study of the Effect of PP and LDPE Thermoplastic Binder Addition on the Mechanical Properties and Physical Properties of Particulate Composites for Building Material Application

2019 ◽  
Vol 964 ◽  
pp. 115-123
Author(s):  
Sigit Tri Wicaksono ◽  
Hosta Ardhyananta ◽  
Amaliya Rasyida ◽  
Feisha Fadila Rifki
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Building Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Waste Recycling ◽  
Plastic Waste ◽  
Particulate Composites ◽  
Water Absorbability

Plastic waste is majority an organic material that cannot easily decomposed by bacteria, so it needs to be recycled. One of the utilization of plastic waste recycling is become a mixture in the manufacture of building materials such as concrete, paving block, tiles, roof. This experiment purpose to find out the effect of addition of variation of LDPE and PP thermoplastic binder to physical and mechanical properties of LDPE/PP/Sand composite for construction material application. In this experiment are using many tests, such are SEM, FTIR, compression strength, density, water absorbability, and hardness. the result after the test are the best composition of composite PP/LDPE/sand is 70/0/30 because its have compression strength 14,2 MPa, while density value was 1.30 g/cm3, for the water absorbability is 0.073%, and for the highest hardness is 62.3 hardness of shore D. From the results obtained, composite material can be classified into construction materials for mortar application S type with average compression strength is 12.4 MPa.

scholarly journals SELECTION OF WIRELESS TECHNOLOGY FOR TRACKING CONSTRUCTION MATERIALS USING A FUZZY DECISION MODEL / BELAIDŽIO RYŠIO TECHNOLOGIJŲ ATRANKA STATYBINĖMS MEDŽIAGOMS STEBĖTI, TAIKANT NEAPIBRĖŽTŲJŲ AIBIŲ SPRENDIMO MODELĮ

2012 ◽  
Vol 18 (1) ◽  
pp. 43-59 ◽  
Author(s):  
Shaohua Jiang ◽  
Won-Suk Jang ◽  
Mirosław J. Skibniewski
Keyword(s):  
Decision Making ◽  
Construction Projects ◽  
Large Scale ◽  
Construction Materials ◽  
Point Of View ◽  
Wireless Technologies ◽  
Scope Of Application ◽  
Fuzzy Decision Model ◽  
Specific Technology ◽  
Selection Of

As the size and scale of construction projects increase, inefficiencies related to the manual operations about field data in current tracking systems are becoming an important issue. While emerging wireless technologies are providing a feasible vision of ubiquitous computing and sensor networks applicable to the large-scale construction industry, it has become even harder to select a suitable technology for tracking construction materials because of the differing functionalities, capabilities, and scope of application of the specific technology. This research proposes a multi-criteria decision-making model that leverages the decision process in choosing various wireless technologies available on the market. To justify the selection of a specific technology, a fuzzy method was adopted to provide an appropriate way to decide among five alternatives (e.g., RFID, GPS, Wi-Fi, Zigbee, and UWB). Fuzzy ranking was obtained from the aggregated fuzzy appropriate index (FAI) based on a person's point of view (optimist, pessimist, or neutral). The results showed that Wi-Fi might be a suitable solution for optimists and neutral persons, but UWB might be the better alternative for pessimists. The results of this research may assist construction engineers in applying reasonable decision-making procedures in a fuzzy environment such as construction sites, and rank the relative importance of the various criteria and alternatives specified in this research. Santrauka Augant statybos projektų mastui, rankinis dabartinių stebejimo sistemų duomenų apdorojimo neefektyvumas tampa svarbia problema. Nors naujos belaidžio ryšio technologijos gali sudaryti galimybę įvesti visur prieinamus kompiuterinius ir jutiklių tinklus, naudojamus plataus masto statybos pramonėje, tampa vis sudėtingiau pasirinkti tinkamas technologijas statybinėms medžiagoms stebėti, nes kiekviena technologija atlieka skirtingas funkcijas, skiriasi jų galimybės ir taikymo apimtis. Šiame tyrime siūlomas daugiakriterinis sprendimų priėmimo modelis, kuris, sprendimų priėmimo procesą pasirenkant rinkoje, siūlomas belaidžio ryšio technologijas išskaido į atskirus lygius. Siekiant pagrįsti tam tikros technologijos pasirinkimą, buvo pritaikytas neapibrežtųjų aibių metodas, pasirenkant geriausią technologiją iš penkių alternatyvų (t. y. RFID, GPS, Wi-Fi, Zigbee ir UWB technologijų). Neapibrežtumo rangas buvo gautas taikant agreguotą neapibrežtumo tinkamumo indeksą (FAI), atsižvelgiant į asmens požiūrį (optimistinis, pesimistinis ar neutralus). Gauti rezultatai parodė, kad Wi-Fi technologija yra tinkama optimistams ir neutraliems asmenims, o UWB technologija būtų geresnė alternatyva pesimistams. Šio tyrimo rezultatai gali padėti statybos inžinieriams priimti pagrįstus sprendimus neapibrėžtoje aplinkoje, tokioje kaip statybos aikštelės, ir suranguoti pagal svarbą įvairius kriterijus bei aptartas šiame tyrime alternatyvas.

New Lightweight Construction Material: Cellular Mat Using Recycled Plastic

2013 ◽  
Vol 594-595 ◽  
pp. 503-510
Author(s):  
T.I.T. Noor Hasanah ◽  
D.C. Wijeyesekera ◽  
Ismail bin Bakar ◽  
Wahab Saidin
Keyword(s):  
Cellular Structure ◽  
Construction Material ◽  
Construction Materials ◽  
Base Material ◽  
Social Benefit ◽  
The Body ◽  
Lightweight Construction ◽  
Ground Condition ◽  
Application Specific ◽  
Design And Construction

Applications of lightweight construction materials enable the design and construction in challenging, difficult and demanding scenarios. Construction materials with enhanced stiffness as in sandwich panels, large portable structures and floating foundations are examples of such materials. The advent of cellular structure technology has actively introduced innovation and enabled design and construction, meeting engineering requirements such as in the construction of the body of air crafts. Cellular mat structures present in the minimum, triple benefits in being lightweight, load sharing and minimising non-uniform deformation. This paper further explores the use of recycled plastic waste as the base material for an innovative geomaterial. The combination of cellular structure, mat structure and use of recycled waste material is a desirable development in manufacturing. Paper also outlines the techno social benefit of adopting such material in construction. Other application-specific benefits related to cellular mats are those like noise reduction, energy absorption, thermal insulation, mechanical damping. This paper specifically presents the development of a new multifunctional lightweight material is been proposed as an invective innovation for highway construction on challenging ground condition.

Sign in / Sign up

Export Citation Format

Share Document