Programmable Droplet Bouncing on Bionic Functional Surfaces for Continuous Electricity Generation

The natural phenomenon of droplets bouncing on various surfaces holds remarkable potential for applications like water transportation, self-cleaning, antifreezing, etc. However, achieving precisely controlled patterned droplet bouncing on functional surfaces with accurately controlled factors like bouncing velocity and trajectory in three dimensions remains a formidable challenge. In this context, a concept of bionic hydrophobic functional surfaces composed of mushroom-like microstructures is introduced. These microstructures are crafted using the projection microstereolithography (PµSL) based 3D printing technique, subsequently coated with a hydrophobic spray. By finely adjusting the geometric attributes and inclination angles of these micromushrooms, the ability is gained to meticulously manipulate the bouncing velocity and trajectory of water droplets. The most optimal performance is demonstrated by a droplet exhibiting a maximal jumping distance and height respectively of 2.5 and 7.1 mm with 50° inclined micromushrooms. Notably, these specially designed micromushrooms orchestrate diverse behaviors in droplet bouncing, encompassing patterned bouncing, antigravity jumps, and directional water transportation. Additionally, the functional surface's adaptable self-cleaning capability facilitates the harnessing of energy from rainfall on large surfaces, offering potential applications in realms, such as self-cleaning mechanisms, droplet capture, water conveyance, and clean energy generation.     

Study of the recrystallization process of AlMgSi alloys containing transition elements

The addition of small amounts of the transition elements such as Zr, Mn and Cr, which have a low solubility in the α-aluminium solid solution and thus form dispersoids, to AlMgSi alloys showed that these elements inhibit recrystallization when the alloys are pre-heated prior to deformation. The formation of coarse particles during casting is mainly due to the presence of Fe. This type of particles found, even, in solution treated samples. The particles, with a diameter exceeding 3 μm, accelerate the recrystallization as they provide good sites for nucleation of recrystallization. Precipitate free zones (PFZ's) developed around the coarse particles favour nucleation of recrystallization by subgrain growth. The presence of dispersoid particles is found to shift the recrystallization energy peak towards higher temperatures. Intermediate annealing before deformation allowed to achieve a high rate of deformation by cold rolling due to the removal of the solute from the matrix by the formation of the hardening phases. Optical and transmission electron microscopy, hardness measurements and differential scanning calorimetry (DSC) were used to study the kinetics of precipitation and recrystallization of the AlMgSi alloys.     

Learning new principles from precedents and exercises

Much learning is done by way of studying precedents and exercises. A teacher supplies a story, gives a problem, and expects a student both to solve a problem and to discover a principle. The student must find the correspondence between the story and the problem, apply the knowledge in the story to solve the problem, generalize to form a principle, and index the principle so that it can be retrieved when appropriate. This sort of learning pervades Management, Political Science, Economics, Law, and Medicine as well as the development of common-sense knowledge about life in general.This paper presents a theory of how it is possible to learn by precedents and exercises and describes an implemented system that exploits the theory. The theory holds that causal relations identify the regularities that can be exploited from past experience, given a satisfactory representation for situations. The representation used stresses actors and objects which are taken from English-like input and arranged into a kind of semantic network. Principles emerge in the form of production rules which are expressed in the same way situations are.     

Silicon implanted super low-noise GaAs MESFET

Super low-nose GaAs MESFETs have been fabricated using direct ion implantation into undoped LEC substrates. Microwave results at 12 GHz include a noise figure of 1.3 dB, with an associated gain of 10.3 dB and a maximum available gain of 14.9 dB.     

Dimensions of creativity in children's drawings: A social-validation study.

Creative drawings of 3 preschool girls (3 and 5 yrs old) were modified using reinforcement procedures in a multiple baseline design. Clear changes were produced in the diversity of color and form. When selected drawings were shown to adult judges, higher ratings of creativity were given for drawings with increased form diversity but not for drawings with increased color diversity. Results are discussed in terms of the role of social validation in defining and encouraging creativity. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infantile trauma, genetic factors, and adult temperament.

"This investigation was concerned with the effects of infantile trauma upon adult temperament, the influence of genetic factors upon temperament, and the possibility of an interaction between early experience and gene structure in their influence upon adult behavior." With mice as the Ss, evidence was obtained which indicated that: genetic factors influence emotionality, timidity, and motility in mice; infantile trauma influences emotionality; and there is an interaction effect of genetic and traumatic factors on timidity. The results are related to Freudian theory. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An evaluation of the effectiveness of forward facing child restraint systems

The objective of this study was to determine the effectiveness of forward facing child restraint systems (FFCRS) in preventing serious injury and hospitalization to children 12-47 months of age as compared with similar age children in seat belts. Data were obtained from a cross-sectional study of children aged 12-47 months in crashes of insured vehicles in 15 states, with data collected via insurance claims records and a telephone survey. Effectiveness estimates were limited to those children between 12 and 47 months of age seated in the back row(s) of vehicles, restrained in FFCRS, regardless of misuse, or seat belts of all types and usage. Completed survey information was obtained on 1207 children, representing 12632 children in 11619 crashes between 1 December 1998 and 31 May 2002. Serious injuries occurred to 0.47% of all 12-47-month olds studied, including 1.72% of those in seat belts and 0.39% of those in child restraint systems. The risk of serious injury was 78% lower for children in FFCRS than in seat belts (odds ratio (OR) = 0.22, 95% confidence interval (CI) = 0.11-0.45, P = 0.001). The risk of hospitalization was 79% lower for children in FFCRS than in seat belts (OR = 0.21, 95% CI = 0.09-050, P = 0.001). There was no difference between the restraint types in preventing minor injuries. As compared with seat belts, CRS are very highly effective in preventing serious injuries and hospitalization, respectively. This effectiveness estimate is substantially higher than older estimates, demonstrating the benefits of current CRS designs. These results provide those educating parents and caregivers population-based data on the importance of child restraint use.     

Acute healthcare utilization by children after motor vehicle crashes

This study, describing the overall patterns of acute healthcare resource utilization by child crash victims (age 15 years and younger), was conducted between 28 July 1999 and 30 November 2000 as part of an on-going large-scale, child-specific crash surveillance system, Partners for Child Passenger Safety: insurance claims from 15 states and the District of Columbia function as the source of subjects, with telephone survey and on-site crash investigations serving as the primary sources of data. A probability sample of 4862 eligible crashes with 7368 child occupants formed the study sample. Our results suggest that for every 1000 children involved in crashes, 3 are hospitalized; 108 are treated and released from an emergency department (ED); 48 are evaluated in a physician's office, urgent care center, or other facility; and 841 receive no care at all. Comprehensive surveillance systems for motor vehicle crashes must capture children treated in physicians' offices, emergency departments, and other healthcare facilities in order to provide accurate estimates of the impact on the health care system related to motor vehicle trauma.     

Protecting the child's abdomen: a retractable bicycle handlebar

A surveillance system in the Emergency Department of a level 1 pediatric trauma center previously identified minor bicycle crashes as a cause of serious child abdominal injury. A discordancy exists between the apparently minor circumstances and serious injuries sustained by child bicyclists who impact bicycle handlebars. The objective of this work was to redesign the bicycle handlebar to reduce the forces transmitted to the child's abdomen during an impact with the handlebars. A retractable handlebar consisting of a spring–mass–damper system was designed to retract and absorb the majority of energy at impact (Patent pending). Because the child remains in contact with the bar after impact, the retracting system also includes a mechanism to damp the outward motion of the handlebar. This prototype will reduce the forces at impact by 50% in a collision similar to those discussed above. A unique methodology of translating research findings into product design produced a novel handlebar that absorbs significant energy that otherwise would be transferred to the child's abdomen when impacting the handlebar.