Experimental Formula Research Articles

Investigation on Factors Influencing Workability of Recycled Aggregates Concrete

In order to investigate factors influencing workability of recycled aggregates (RA) concrete, such as water amount, sand ratio and RA replacement percentage, 10 pitch of RA concrete was prepared for measurement of workability and a formula was used for calculating effect of water amount on slump of RA concrete. Experimental results and formula induction indicated that there are logarithmic relationship between flowability of fresh concrete and water amount and ratio of aggregates to cement . The flowability will logarithmically increase with increase of water amount and decrease of aggregates cement ratio. The optimum sand ratio for RA concrete can be determined by measurement of slump. Slump decreases with RA replacement percentage and there is a very good linear relationship between them. When water amount increases, slump increases and when replacement percentage of RA increases, slump decrease. Under different water amount, effect degrees of replacement percentage of RA on slump are very similar and under different replacement percentage of RA, effect degrees of water amount on slump are also very similar.

Buffer design for availability: a new simulative study in case of infant and random failures

In automatic production systems, the size of intermediate buffers, significantly affects the success of the production system, especially when their functions is to protect the system from the inevitable processing time fluctuations caused by machine disruptions. In Battini et al. (2009), the authors provided a new experimental formula to define the optimal buffer size to maximise throughput without the need for oversized machines. The authors observed only ‘wear-out failures’, in which the failure rate increases with time. In order to better understand the potential benefits of previous results and extend their applications in industrial contexts, a new simulation study is now presented, with reference to all those interesting industrial cases in which production flow lines are largely affected by infant failures or random machine failures. The final results show a completely new experimental matrix that cover all the possible kinds of failures, able to work in different industrial settings and under dif...

1165 EXPERIMENTAL INVESTIGATION OF BOUNDARY LAYER TRANSITION AND SEPARATION ON ROTATING SPHERE IN AXIAL FLOW

We used a low turbulence wind tunnel that we did build it especially for studying instability and transition problems on rotating bodies. In this paper at first we study effect of rotational Reynolds number on the Transfer velocity. Also we study turbulent characteristics of flow in both laminar separation and turbulent separation case on the sphere. We study about transitional Reynolds numbers on the rotating sphere in axial flow and validate our results by some other published works. Also we use smoke visualization to showing transition and separation mechanisms in this case. We suggest some experimental formulas to approximate transfer velocity and transitional Reynolds numbers on the rotating sphere. Our experiments validate them in all cases that we examine them. Finally the oscilogram of velocity fluctuations in some different cases are shown in the paper, we can see sinusoidal fluctuations in velocity diagram in spiral vortices region.

OS1919 斜め衝突におけるクレータ形状とイジェクタサイズ

The effects of oblique impact angle on ejecta fragment size were investigated by striking aluminum alloy 6061-T6 targets with 3.2-mm-diameter aluminum alloy 2017-T4 spheres at velocities 4 km/s. The two-stage lighet-gas gun at the Institute of Space and Aeronautical Science (ISAS)/ Japan Aerospace Exploration Agency (JAXA), was used for the experiments. The cumulative number of ejecta was proportional to the square of the vertical-direction component of the impact velocity. The experimental formula for the cumulative number distribution of ejecta size was created using bilinear exponential distribution.

20809 超音波浮遊液滴の相変化過程における伝熱流動特性(086-3【熱流体工学のフロンティア(3)】)

Container-less processing using levitation technique could prevent heterogeneous nucleation and contamination from container wall. Acoustic levitation is expected to be used for analytical chemistry and manufacturing new materials. Thus,It is important to gather the knowledge about acoustically levitated droplet. The purpose of this study is to investigate the heat transfer and flow characteristic of an acoustically levitated droplet. The following results were obtained from experiments. Evaporation process of levitated droplet was observed. Surface temperature lowers after levitation and volume decreases while levitation. External flow was observed and differs by water and ethanol. Toroidal vortex near the ethanol droplet interface was observed. By measuring temperature,temperature distribution near the droplet surface was found. Finally, heat transfer coefficient was estimated and it was higher than the existing experimental formula.

Characteristics of Arc Voltage for High-Current Air Arc under Arrangement of Deion Plates and Approach to Improving Availability of the Plates

In this study, (i) effect of deion plates on arc voltage and (ii) appropriate arrangement of the plates were investigated in order to develop a design guide of a circuit breaker which is able to interrupt fault current (> several kA). As for evaluation (i), improved effect on arc voltage under arrangement of the plates were evaluated quantitatively in association between arc voltage and the design factors which are current, arc length, internal pressure and number of the used plates. As the result, it was found that arc voltage rises 19.2V by number of split arc between the plates and electrical field in arc rises about 3V/mm under high internal pressure above 0.2MPa-g. Experimental formula constituted by the design factors for estimation of arc voltage was developed on the basis of the improved effect on the voltage. Since the formula is able to estimate actual arc voltage with a margin of error within about 7%, it would be provided as effective guidelines to design arc extinguishing chambers. As for evaluation (ii), dependences of the availability of used plates on electromagnetic force to drive arc were evaluated. As the result, it is found that the plates are used effectively by exerting above a certain electromagnetic force (e. g., above 5N in case of 5kA) on the arc between the electrode and the plate. Therefore, the improvement of magnetic design near the electrodes, especially the movable electrode, or the arranging enough space to drive the arc between the electrode and the plate would be improved availability of the used plates.

학부용 편광계와 543 nm에서 설탕의 비회전 측정

광학 활성의 측정은 고분자, 광통신, 천문학, 물리학 등과 관련된 분야에서 매우 중요한 주제가 되고 있다. 따라서 이와 같은 경향은 이 주제를 학부 실험에 반영되도록 할 필요가 있다. 이 실험에서는 파장이 543 nm인 헬륨-네온 레이저와 학부용으로 시판되는 파스코 사의 검출기, 회전 엔코더 및 자료 수집기를 사용해서 저비용으로 믿을만한 결과를 주는 편광계를 구성하고 관련 이론과 실험식을 제시하였다. 장치 성능을 검증하기 위해 반파장판을 표준 시료로 사용했으며, 그 후 농도가 30 %인 설탕 용액을 측정 시료로 사용해 비회전을 측정해 보았다. 설탕의 비회전 측정 결과는 +76 deg.cc/g.dm로써, 기존의 CRC 자료들의 내삽을 통해 추정된 값과 거의 동일했으므로, 대부분 학부 수준의 실험에서도 충분히 수용 가능하다고 판단되었다. Measurements of the optical activity become very important issues in fields related to polymers, optical communications, astronomy, physics and many more. Hence it need to introduce this subject in our regular curriculum. In this experiment, an inexpensive, reliable, motorized polarimeter system which is suitable for undergraduate courses is constructed with PASCO's well-known Science Workshop 750 and a rotational motion sensor and light sensor, and the system is presented along with its experimental formulas. After responsivity of this system was checked by a half wave plate, and some repetitive experiments with 30% sucrose solution at 543.8 nm were performed. Comparing the experimental result with two calculated values from CRC data[1] showed that the specific rotation of the sucrose sample could be strongly suggested to be around +76 deg.cc/g.dm and it was an amply acceptable result for most undergraduate level courses.

Plasma carotenoid concentrations of infants are increased by feeding a milk‐based infant formula supplemented with carotenoids

Human milk is the gold standard of infant nutrition and is a source of important substances, including carotenoids. Infant formulas are designed to mimic the composition and/or performance of human milk, although currently carotenoids are not routinely added to US infant formulas. The aim of this study was to assess plasma concentrations of β-carotene, lutein and lycopene 56 days after feeding infants milk-based infant formula without (CTRL) or with different concentrations of added carotenoids (L1 and L2). Plasma carotenoid concentrations increased in infants fed carotenoid-supplemented formulas as compared with the control formula with no added carotenoids. At study day 56, infants fed the supplemented formulas (L1 and L2) had mean plasma lutein, β-carotene and lycopene concentrations that were within the range of a concurrent group of human milk-fed infants (HM). Anthropometric measurements were comparable among all study groups. Plasma carotenoid concentrations of infants fed the supplemented formulas were within the range of the HM group and are consistent with reported plasma carotenoid ranges in human milk-fed infants. The experimental formulas were well tolerated and anthropometric measurements were comparable among all study groups.

Modeling study on axial wetting length of meniscus in vertical rectangular microgrooves

In this work, the traditional model for predicting axial wetting length of meniscus in vertical microgrooves is introduced firstly. The traditional model may cause inaccurate results in predicting wetting length in vertical microgrooves because of the assumption of round meniscus in cross sections of microgrooves and the way of calculating curvature. In order to develop this model and make it more accurate, a revised micro-PIV system is built to test the meniscus shapes in cross sections of vertical and horizontal microgrooves, and the experimental results prove that the real shapes of meniscus are parabolic other than round. The fitting formulas of meniscus shapes are obtained with software Origin 7.5. Based on experimental results and fitting formulas, the traditional model is revised by changing the way to calculate curvature. In the modified model, the curvature for calculating axial wetting length of meniscus equals average curvature of meniscus in cross section of vertical microgrooves minus the average curvature of meniscus in cross section of horizontal microgrooves. It is proved that the modified model can predict the wetting length in vertical microgrooves better than the original model. The average difference between experiment and modified model is 2.5% while that between experiment and traditional model is 174.2%. The disadvantage of the modified model is that using the new model to predict wetting length needs to know the real shapes of meniscus in vertical and horizontal microgrooves.

Sound Pressure Levels in Rooms: A Study of Steady State Intensity, Total Sound Level, Reverberation Distance, a New Discussion of Steady State Intensity and Other Experimental Formulae

Sound Pressure Levels in Rooms: A Study of Steady State Intensity, Total Sound Level, Reverberation Distance, a New Discussion of Steady State Intensity and Other Experimental Formulae

Influence of Charges Shape on a Closely Air Blast Loading

The purpose of the present paper is to investigate the influence of charge shape on the air blast loading near the explosive. By using MSC. DYTRAN, the air blast loading of spherical charge, cubical charge and cylindrical charge with the same weight were simulated. After the characters of shock wave, peak pressure and impulse of such three charges were compared, it can be seen that there are different decay law for peak pressure of cylindrical charge, cubical charge, spherical and experiment formula. There are also different magnitude relation for the impulse at different scaling distance.

응력파속도를 이용한 부착식 PSC 텐던의 긴장력 추정

This study proposes an experimental formula that can estimate the applied tensile stress of a bonded PSC by measuring a longitudinal stress wave velocity of tendon. To develop practical formula, the various bonded PSC specimens are constructed with different levels of prestresses. For all the bonded PSC specimens, the longitudinal impact-echo tests are repeated with various experimental conditions. Considering a few influence factors such as temperature, length and the number of strands, the application of the law of similarity results in a nondemensional experimental formula that could estimate existing tensile stress on tendon by measuring its longitudinal stress wave velocity. Next, a feasibility study of proposed approach has been conducted for a real reactor building containment. The estimated stress levels of two vertical tendons embedded in the nuclear plant are close to their design values.

Sound Pressure Levels in Rooms: A Study of Steady State Intensity, Total Sound Level, Reverberation Distance, a New Discussion of Steady State Intensity and other Experimental Formulae

In this publication we include all, or almost all, the valid formulas of sound levels in different types of rooms. We will explain all the theoretical basis of each of them, starting with reflected intensity, both classical and revised theories, the total sound level and its uses in concert venues. We will also deal with empirical formulas mainly for classrooms, churches and religious buildings and industrial use. However, the main significance of this work is not only the wide range of formulas exposed but also that we have found the explanation of why the reverberation radius, or distance radius, cannot exist in the revised theory. This finding can help that the revised theory of M. Barron be slightly modified to apply it to any room for several uses, other than concerts

CO2무 배출 침탄 열처리된 SCM415H 소재의 기계적 성질

Free(이산화탄소무배출), Mechanical Properties(기계적성질)초록: 진공침탄법은이산화탄소의발생이없는친환경적인열처리방식으로알려져있다.그러나진공침탄법은탄화수소가스(메탄, 프로판)를노내에직접공급하여열분해하는과정을거침으로써노내에그을음이발생하여안정적인조업이불가능한단점이있다.최근에는이러한단점을극복하기위한불포화탄화수소인아세틸렌가스를이용한진공침탄법이활발히연구되고있다.본논문에서는아세틸렌가스를이용한진공침탄방식의침탄및확산시간을변수로하여여러가지조건에서열처리를진행한후가스침탄열처리된소재와기계적성질을비교분석하여이산화탄소무배출진공침탄열처리방법의활용가능성을확인하였다. 연구결과본연구에서시도된진공침탄법은가스침탄에서나타나는입계산화층이발생하지않았으며경도값은진공침탄시험편의유효경화깊이가29.8%크게나타났으며인장강도는가스침탄보다10%낮게나왔으나허용치를충분히만족하는수준이었다.Abstract: Vacuum carburizing is supposed to be the superior process to the gas carburizing. However, thevacuum carburizing has the stage in which hydrocarbon gas is supplied into the furnace to be pyrolysis, andconsequently the stable heat treatment is hard to achieve due to the soot from the hydrocarbon pyrolysis.Recently, many studies have been made which utilize acetylene gas to overcome this defects. In this paper,the carburizing and the diffusion periods have been selected based on the Harris experimental formula, andthe mechanical properties of the vacuum carburized specimen have been compared with those of the gascarburized SCM415H specimen to identify the feasibility of the CO

Hydraulic jump basins with wedge-shaped baffles

This laboratory study deals with the hydraulic jump properties for an artificially roughened bed with wedge-shaped baffle blocks. The experiments were conducted for both smooth and rough beds with a Froude number in the range of 3.06≤F 1≤10.95 and a relative bed roughness ranging 0.22≤K R≤1.4. The data from this study were compared with those of rectangular baffle blocks. New experimental formulae were developed for determining the sequent depth ratio and the hydraulic jump length in terms of the inflow Froude number and relative bed roughness. Belanger’s jump equation of a rectangular channel was extended to account for the implications of the bed shear stress coefficient attributable to channel bed roughness. It was found that, in comparison with the smooth bed, the wedge-shaped bed roughness reduced the sequent depth of the hydraulic jump by approximately 16.5% to 30% and the hydraulic jump length by approximately 30% to 53%.

Tolerance, Bone Mineral Content, and Serum Vitamin D Concentration of Term Infants Fed Partially Hydrolyzed Whey-based Infant Formula

The objective of the study was to assess the tolerance (intake, incidence of spit up/vomit, and stool patterns), bone mineral status, and vitamin D status of healthy, term infants fed one of two partially hydrolyzed bovine whey protein infant formulas from birth to 56 or 84 days of age. The control formula was commercially available and was compared to an experimental formula. Eighty-nine term infants were enrolled in the study and 74 (83%) completed the study. The control formula had similar vitamin D but lower calcium and phosphorus content and contained palm olein oil and lactose compared to the experi- mental formula. Infants fed the experimental formula exhibited significantly greater serum 25-OH vitamin D levels at 2 months of age, significantly greater bone mineral content as assessed by dual-energy x-ray absorptiometry at 3 months of age and softer stools during the study period compared to infants fed the control formula. No differences were observed between groups for formula intake, incidence of spit up/vomit, anthropometric measurements, or serum concentrations of calcium, phosphorus, skeletal alkaline phosphatase, or parathyroid hormone. The results suggest that both study formulas are safe but differ in the metabolic response of infants fed the formula. Bone mineral content in these infants reflected differences in levels of nutrients important to calcium between two formulas over the short-term. Long-term implications and clinical relevance of these findings are unknown and require further study. These results provide additional knowledge regarding the typical vitamin D status as assessed by serum 25-OH vit- amin D of healthy term formula-fed infants.

Study on Tool Life of Surface Textured Tool in Dry Cutting of Ti-6Al-4V Alloys

Surface textured tools were fabricated by laser beam machining. Dry cutting of Ti-6Al-4V alloys was carried out with these surface textured tools and conventional tools for comparison. The cutting temperature, tool flank wear and surface roughness of processed workpiece were measured. The experimental formulas of tool life based on DOT method were developed. Results show that the surface textured tool can reduce the surface roughness of workpiece, and the tool life of surface textured tool is improved by 15% or so compared with the conventional one.

Experimental Study on Cutting Forces in Turning Aluminum-Silicon Alloy

Cutting force experiments in turning aluminum-silicon alloy were carried out with cement carbide tool YG8. Experimental formulae of cutting force, back force and feed force were determined based on multi-variable linear regression analysis, and they were verified by analysis of variance, the results showed that the regressed models could be used to predict cutting force under certain conditions.

A General Method for Quantifying the Amorphous Phase in Nano Polycrystalline Materials

The grain boundary area has a great influence on the polycrystalline material properties and in nano crystallized metals. It could be considered as a glass metal phase in addition to crystallites in a composite structure. In this research, a general procedure for directly quantifying the crystalline and amorphous phases is introduced by using an x-ray diffractometry technique. Nickel with a nano crystalline structure was deposited onto pure copper samples with grain sizes of between 17 to 124 nm by an electroplating technique. A combination of measuring the area of the XRD pattern characteristic peaks and x-ray background scattering were used for the estimation of the crystalline and amorphous volume percentages. The results show that there is a non-linear relationship between the percentage of the crystalline phase calculated by the geometrical method and the area of the selected XRD peak. An experimental formula is suggested for the calculation of the crystalline phase volume percentage of the nano structure nickel samples based on the (200) x-ray peak area.

주류유동에서 단일 및 이중 수직분사 분무특성

연소실 내의 주류 공기유동에 미치는 영향을 최소화하면서 미립화 및 혼합특성을 향상시키기 위한 방법으로 주류공기 유동에 대해 수직방향의 연료분사 방식이 실용 엔진에서 많이 사용되고 있고, 관련 연구도 활발히 보고되고 있다. 본 연구는 가스터빈이나 램젯 엔진에서 사용되고 있는 수직분사의 분무특성은 실험적으로 조사하고, 단일 및 이중 수직분사에 따른 침투길이를 측정함으로써 선행연구에 의해 보고된 결과와 비교하였다. 또한 압력과 모멘텀 플럭스비 변화에 따른 침투길이, 분무입경 등의 분무 특성을 연구하였다. 특히, 이중 수직분사의 침투길이는 단일 수직분사의 침투길이에 비해 전단의 수직분사의 영향으로 후단의 수직분사 길이가 약 20% (Lh=4mm) 증가함을 확인할 수 있었다.