Optimization of microwave‐assisted extraction for anthocyanins,polyphenols, and antioxidants from raspberry (Rubus Coreanus Miq.) using response surface methodology

Anthocyanins (Acys), polyphenols, and antioxidants were extracted from raspberry (Rubus Coreanus Miq.) using a highly efficient microwave‐assisted extraction technique. Different solvents, including methanol, ethanol, and acetone, were tested. The colors of the extracts varied from light yellow to purple red or dark red. SEM and other nutrient analyses verified that ethanol was the most favorable medium for the microwave‐assisted extraction of raspberry due to its high output and low toxicity. Effects of process parameters, including microwave power, irradiation time, and solvent concentration, were investigated through response surface methodology. Canonical analysis estimated that the highest total Acys content, total polyphenols content, and antioxidant activity of raspberry were 17.93 mg cyanidin‐3‐O‐glucoside equivalents per gram dry weight, 38.57 mg gallic acid equivalents per gram dry weight, and 81.24%, respectively. The polyphenol compositions of raspberry extract were identified by HPLC with diode array detection, and nine kinds of polyphenols were identified and quantified, revealing that chlorogenic acid, syringic acid, and rutin are the major polyphenols contained in raspberry fruits. Compared with other fruits and vegetables, raspberry contains higher Acy and polyphenol contents with stronger antioxidant activity, suggesting that raspberry fruits are a good source of natural food colorants and antioxidants.     

一款基于树莓派的便携式智能灭火器设计

设计了一款基于树莓派的便携式智能灭火器,该设计过程包括采用瓶体模块设计,存储模块设计,远程监测与报警模块设计.其中,瓶体外部采用ABS阻燃材质,内部采用一种用于气溶胶罐的铝合金铝合金;存储模块采用无压存储S型气溶胶的方式;远程监控系统中使用树莓派作为中央控制器,辅以各种传感器采集信息,然后通过外部方式远程传输数据,实现...     

基于树莓派+Arduino的WiFi反馈控制系统的研究

随着物联网的发展,智能家居越来越被人们重视.为了解决智能家居中使用ZigBee高成本的问题,本文介绍了以树莓派为主的控制端,Arduino开发板和无线模块作为数据反馈端,实现了在WiFi环境下,对LED灯的开关控制,并反馈LED灯真实亮灭情况.简化了智能家居的控制结构,并降低了成本.     

基于改进YOLOv5的树莓派火焰识别系统

火灾会对人员与财产安全造成巨大危害,如何迅速、准确地检测火焰出现具有重要意义。为实现高大空间条件下火焰的准确识别,设计了一种具有二自由度、可全方位检测环境情况的红外摄像头,并结合深度学习对目标检测算法YOLOv5进行改进;利用K-Means聚类算法匹配出9个聚类中心宽高维度替换原网络anchor参数;考虑了目标框相对比例,对损失函数进行优化,并用于树莓派上实现火焰识别。测试结果表明：改进的YOLOv5算法在树莓派上单张检测耗时2.9 s,较无改进YOLOv5算法减少78%;系统查准率为100%,识别目标框置信度均在0.9以上,能够快速准确识别出火焰。     

Application of Internet of Things Micropower Smart Switch in Temperature Monitoring

This study uses the smart phone with the Android system to construct a cloud-side smart switch system in the client-server architecture with the Android open platform system, using microprocessors (MCU 16F690) as the thermostat controller and combined with Raspberry Pi. The computing technology extends the control of the constant temperature from the local to the cloud, allowing the user to view the temperature status recorded by the cloud server using the smart phone application (App) or web browser. It can even remotely control the heating power of the smart switch for the heating device in the Internet control environment and use the proportional-integral-derivative (PID) control and the pulse-width modulation (PWM) technology to achieve intelligent constant temperature control. The proposed control system uses the expert PID control as the core to calculate the duty cycle of the PWM signal to control the power output of the smart switch for the constant temperature water tank. The experiment results verify the effectiveness of the proposed system.     

A lightweight portable intrusion detection communication system for auditing applications

The goal of this paper is to develop, deploy, test, and evaluatea a lightweight portable intrusion detection system (LPIDS) over wireless networks by adopting two different string matching algorithms: Aho‐Corasick algorithm and Knuth‐Morris‐Pratt algorithm (KMP). Thus, this research contributes in three ways. First, an efficient and lightweight IDS (LPIDS) is proposed. Second, the LPIDS was developed, implemented, tested, and evaluated using Aho‐Corasick and KMP on two different hardware platforms: Wi‐Fi Pineapple and Raspberry Pi. Third, a comparative analysis of proposed LPIDS is done in terms of network metrics such as throughput, power consumption, and response time with regard to their counterparts. Additionally, the proposed LPIDS is suggested for consultants while performing security audits. The experimental results reveal that Aho‐Corasick performs better than KMP throughout the majority of the process, but KMP is typically faster in the beginning with fewer rules. Similarly, Raspberry Pi shows remarkably higher performance than Wi‐Fi Pineapple in all of the measurements. Moreover, we compared the throughput between LPIDS and Snort, it is observed and analyzed that former has significantly higher throughput than later when most of the rules do not include content parameters. This paper concludes that due to computational complexity and slow hardware processing capabilities of Wi‐Fi Pineapple, it could not become suitable IDS in the presence of different pattern matching strategies. Finally, we propose modification of Snort to increase the throughput of the system.     

Loop-type interface for concurrent solvent evaporation in coupled HPLC-GC. Analysis of raspberry ketone in a raspberry sauce as an example

Presently, two coupling techniques are used for directly introducing HPLC fractions into capillary GC: The retention gap technique (involving negligible or partially concurrent solvent evaporation) and fully concurrent solvent evaporation. While the former involves use of a conventional on-column injector, it is now proposed that concurrent solvent evaporation technique be carried out using a switching valve with a built-in sample loop. The technique is based on the concept that the carrier gas pushes the HPLC eluent into the GC capillary against its own vapor pressure, generated by a column temperature slightly exceeding the solvent boiling point at the carrier gas inlet pressure. Further improvement of the technique is achieved by flow regulation of the carrier gas (accelerated solvent evaporation) and backflushing of the sample valve (improved solvent peak shape). Concurrent solvent evaporation using the loop-type interface is easy to handle, allows transfer of very large volumes of HPLC eluent (exceeding 1 ml), and renders solvent evaporation very efficient, allowing discharge of the vapors of 1 ml of solvent through the column within 5–10 min.     

基于Raspberry Pi的家庭附网存储系统的设计与实现

为解决当前家庭用户大量数据下载、存储和共享的问题,提出了一种新的基于树莓派硬件平台的家庭附网存储系统.设计搭载了基于Debian的Linux操作系统,提供了基于CIFS/SMB、NFS和F1P协议的网络异构系统的文件共享,并实现了多种方式的脱机下载.系统将RAID技术和LVM技术相结合,并且利用Bypy同步百度云空间,提高了设备中数据的读写速率和系统的安全性,同时采用B/S模式的Web管理系统,用户可以通过浏览器对NAS设备进行控制和管理.通过测试数据表明,系统稳定可靠,具有数据传输速度快、安全性高、可扩展性好等优点.     

Raspberry PI在课程设计中的应用

随着技术的不断提高,各种医疗仪器设备集成化、智能化的趋势也越来越明显,从而对毕业生的要求也越来越高.文中主要探讨了一种刚刚兴起的微型计算机-Raspberry PI,一种香烟盒大小的超小型电脑在课程设计中的应用.通过使用这种超小型计算机来进行简单项目的开发,来提高学生的动手能力与独立解决问题的能力,使学生时现代化医疗仪器的软硬件构成有一个较为深入的认识.     

基于NodeMCU智能语音交互家居系统设计

针对传统家居家电设备很难直接与市场上的语音助手结合,同时高技术产品价格很难惠民,智能家居控制系统因设计成本过高很难实现普及的现象,本文提出将树莓派和NodeMCU开发板联合开发一款性价比极高的智能语音交互家居系统.设计使用树莓派4B+在Linux系统下运行百度云平台提供的SDK加上麦克风阵列和CSI摄像头实现语音识别、...