Site-Selective Aliphatic C–H Chlorination Using N -Chloroamides Enables a Synthesis of Chlorolissoclimide

Methods for the practical, intermolecular functionalization of aliphatic C-H bonds remain a paramount goal of organic synthesis. Free radical alkane chlorination is an important industrial process for the production of small molecule chloroalkanes from simple hydrocarbons, yet applications to fine chemical synthesis are rare. Herein, we report a site-selective chlorination of aliphatic C-H bonds using readily available N-chloroamides and apply this transformation to a synthesis of chlorolissoclimide, a potently cytotoxic labdane diterpenoid. These reactions deliver alkyl chlorides in useful chemical yields with substrate as the limiting reagent. Notably, this approach tolerates substrate unsaturation that normally poses major challenges in chemoselective, aliphatic C-H functionalization. The sterically and electronically dictated site selectivities of the C-H chlorination are among the most selective alkane functionalizations known, providing a unique tool for chemical synthesis. The short synthesis of chlorolissoclimide features a high yielding, gram-scale radical C-H chlorination of sclareolide and a three-step/two-pot process for the introduction of the β-hydroxysuccinimide that is salient to all the lissoclimides and haterumaimides. Preliminary assays indicate that chlorolissoclimide and analogues are moderately active against aggressive melanoma and prostate cancer cell lines

Measuring temperature distribution on the surface of flying missiles

There are problems associated with flight of objects such as rockets after exceeding sound barrier. One of them is heating up their body during the flight, especially at low altitudes. Overheated surface of rocket leads to serious consequences, such as rapid destruction of material components of missile. It could cause an interference with target tracking signal if it is on the spectral range of missile optoelectronic detecting head. It can cause destruction of flying missile in extreme cases. In addition, temperature increase causes an increase of drag force of object what directly influences its ballistic parameters. The subject of the paper is to present a concept of experimental set-up to test the heating of missile body at flight. The set-up is based on a wind tunnel. Four missiles were selected for initial analysis in order to test some typical designs for significantly different flight velocities and aerodynamics. Boundary layer at flow around the surface, determining temperature field of missile, the local distribution of heat transfer coefficients on the sphere and exemplary distribution of temperature and pressure on the sphere during flow around, distribution of Nusselt numbers for different velocities of flow around roll, numerical model of rockets, distribution of Mach number, temperature field and velocity vectors are presented

Selected problems of designing giuded aerial target imitator ICP 12S6

W artykule przedstawiono podstawowe zagadnienia związane z modernizacją balistycznego imitatora celu powietrznego ICP. Celem modernizacji jest zbudowanie kierowanego imitatora umożliwiającego poprawę wyszkolenia wojsk przeciwlotniczych.Basic problems of modernization of existing ballistic aerial target imitators ICP are presented in the paper. The aim of the modernization is to develop a new design of the guided imitator to improve training of anti-aircraft military units

Miniature bomb concept for unmanned aerial vehicles

This paper presents the design methodology of a small guided bomb for Unmanned Aerial Vehicles. This kind of next-generation munition has recently gained a lot of attention in the military market. The bomb is planned to be equipped with inertial measurement unit and infrared seeker.The nose shape and fin optimization procedure was described shortly. Aerodynamic characteristics were calculated by means of theoretical and engineering-level methods. The flight dynamics model of the bomb was obtained and implemented in Simulink software. The numerical simulations of uncontrolled and controlled trajectories were compared. The results indicate that the usage of such a guided small munition, like the designed bomb, might improve significantly the offensive capabilities of Unmanned Aerial Vehicles

Construction of a dual metric-semantic map of the mobile robot environment based on data from a 3D laser scanner

W artykule przedstawiono metodę budowy hybrydowej rastrowo-obiektowej mapy otoczenia mobilnego na podstawie wskazań skanera laserowego 3D. Chmura punktów jest zapisywana w postaci zbioru wektorów normalnych. Składowe wektora są reprezentowane jako składowe RGB. Przeprowadzana jest segmentacja obrazu, a następnie dokonuje się klasyfikacji semantycznej. W procesie klasyfikacji wykorzystuje się cechy Haara oraz systemy regułowe. Każdy wykryty obiekt jest przypisywany do pewnej komórki mapy rastrowej. Mapa utworzona w ten sposób może być następnie wykorzystana w algorytmie nawigacyjnym - ułatwia współpracę robot-człowiek oraz planowanie trasy. Metoda jest kontynuacją algorytmu opisanego w artykule pt." Segmentacja danych otrzymanych z dalmierza laserowego 3D".The major goal of our current research is to build a dual grid-based and semantic map of an unknown indoor environment based on data obtained from a 3D laser scanner. In this paper main steps concerning object classification are presented. A point cloud from the 3D scanner is transformed into a set of normal vectors, which are then represented as a RGB raster image where each color component corresponds to x, y, z coordinates of the vectors. In the next step we apply some standard methods from image analysis, like flood-filling and object detection using Haar-like features, in order to perform segmentation and find objects of our interest in the examined scene. Afterwards we use 3D geometrical information and relation between the detected objects in our classification process. If a semantic meaning can be assigned to any object it is used for building a dual metric-semantic map of the environment. Such a map should serve as a basic element for human-robot interaction

A mobile robot navigation with use of CUDA parallel architecture

In this article we present a navigation system of a mobile robot based on parallel calculations. It is assumed that the robot is equipped with a 3D laser range scanner. The system is essentially based on a dual grid-object, where labels are attached to detected objects (such maps can be used in navigation based on semantic information). We use a classical SMPA (Sense - Model - Plan - Act) architecture for navigation, however, some steps concerning object detection, planning and localization are parallelized in order to speed up the entire process. The CUDA (Compute Unified Device Architecture) technology allows us to execute our algorithms on many processing units with use of a inexpensive graphics card which makes it possible to apply the proposed navigation system in a real time

3D laser data segmentation

Otoczenie robota - wnętrze budynku jak i obszar znajdujący się na zewnątrz może być podzielony na fragmenty, którym następnie możemy przypisać pewne znaczenie semantyczne. Przed przystąpieniem do dokonywania klasyfikacji należy jednak dokonać filtracji i segmentacji danych pomiarowych. W poniższym artykule przedstawione zostaną wyniki segmentacji chmury punktów, którą otrzymujemy na podstawie wskazań laserowego skanera 3D. Zastosowano nowatorską technikę, w której dane pomiarowe zamieniane są na postać kartezjańską, następnie obliczane są wektory normalne do powierzchni, na której punkty leżą. Składowe wektora są normalizowane i zapisywane w reprezentacji RGB. W wyniku opisanej transformacji powstaje kolorowy obraz. Dzięki temu problem segmentacji danych w przestrzeni 3D jest sprowadzony do zadania analizy kolorowych obrazów. Umożliwia to zastosowanie znanych z wizji algorytmów: usuwania szumów, rozrostu ziarna i segmentacji. Przeprowadzone eksperymenty w pomieszczeniu zamkniętym i na zewnątrz budynku potwierdziły efektywność przyjętej metody.Map building of unknown environment is a part of a navigation system and is one of the most important topics in modern mobile robotics. Many environment representations have been proposed. One of the most popular is 2D representation which has many limitations, for example the height of obstacles is not taken into account. In the last decade 3D sensors are being more popular which enable 3D map building. In our approach the laser scans a scene and gives 2D data. The rotating support rotates the laser vertically, which allows to make 3D scans. The cloud of points is transformed into a set of normal vectors. The coordinates of a vector are represented as: red, green and blue colors. And 3D information is represented as 2D color image. The segmentation of the RGB image is performed using classical image processing methods. 2D areas are transformed into a 3D representation and classified. Experimental results validated the proposed approach and showed the benefits of using classical method of image processing for 3D data segmentation