The Analysis of 3D Printer Dust for Forensic Applications,,

3D printers are becoming increasingly efficient and economical, and thus more widespread and easily accessible to consumers and businesses. They have been used to print nefarious objects such as guns and suppressors. Previous research has documented the release of dust particles during the printing process; however, little has been written about the morphology and chemical features that define the dust emitted by these printers. This study was undertaken to recover, analyze, and identify the dust produced during the printing process in the context of forensic trace evidence analysis. Samples were collected from a variety of 3D fused deposition modeler printers, representing both consumer and commercial grade models. This work focused on printers that use thermoplastic filaments composed of acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA), two of the most commonly used filament polymers. Swabs were used to collect dust within the printer chamber and then processed to isolate the dust particles. Particles produced from ABS filaments are most easily recognized via light microscopy through a combination of color, morphology, and fluorescence. The composition of these particles can be confirmed through analysis by either FTIR or Raman microspectroscopy. These methods can also be used to identify ABS fillers and pigments within the printer dust particles. In contrast, dust from PLA printers consistently contained finer, submicron-sized particles that could be observed by field emission scanning electron microscopy. Because the size of the particles precludes their identification using vibrational spectroscopy methods, pyrolysis-GC-MS was used to confirm the presence of PLA.     

Toner Particles as Forensic Evidence: Microanalytical Characterization of Known Toner and Recognition of Toner in Environmental Samples*†‡

Modern printing toners represent a prime example of subvisible particles that can be easily transferred to hands, clothing, and other surfaces. To explore the potential evidentiary value of toner particles, toner samples were collected from known printer cartridges and characterized by various microanalytical techniques to establish the properties most useful for recognition, identification, and comparison. Environmental samples (i.e., dust) were then collected from various locations at varying distances from toner-based printers, using both tape lifts and carbon adhesive stubs, to assess the possibility of detecting toner. By light microscopy, toner can be recognized on the basis of particle size and shape, as well as color. Further examination of the micromorphology in the field emission scanning electron microscope reveals characteristic morphologies and differences in surface texture and shape among toner sources. Raman spectroscopy provides chemical identification of the pigment (or pigment class) and, in some cases, also permits identification of the polymer component. While black and blue pigment chemistry remained constant among toner varieties that were studied (copper phthalocyanine and carbon black), variation in yellow and magenta pigments was observed. Analysis of dust samples collected from various environments demonstrated that while toner is consistently detectable in close proximity to printers (within 2 feet), it also can be detected in dust collected in nearby rooms. This research demonstrates that toner particles can be located, characterized, and discriminated, using a suite of microanalytical methods that are applicable to forensic casework.     

21世纪初危机应对中的俄罗斯国家形象塑造

危机发生后,一国政府如何应对危机一定程度上损害或修复着国家形象。21世纪初的十来年,世界上发生了一系列与俄罗斯相关的国内外危机,面对这些事件,在苏联解体后俄罗斯国际形象受损的颓势背景下,俄罗斯政府积极应对,既灵活务实,又顽强有力,客观上塑造了资源丰富、经济回升、政局稳定、政权有力、追求多极化、在国际上有发言权的世界大国形象。     

利用彩色文件上的图文特征鉴别喷墨打印机品牌

目的通过彩色文件上的图文特征鉴别喷墨打印机的品牌。方法在体视显微镜下观察采用不同喷墨机理的惠普、佳能和爱普生三大品牌喷墨打印机打印的彩色图文。结果通过对彩色图文上六种墨迹形态特征的比较,发现三大品牌喷墨打印机打印的彩色图文存在明显差异。结论依据这六种特征对三大品牌的喷墨打印机进行鉴别。     

单一颜色商标注册保护的可行性分析及启示

2014年5月1日起正式实施的新商标法并未纳入单一颜色商标，这成为本次《商标法》修改的一大遗憾。域外美欧等发达国家已经形成了较为成熟的单一颜色商标注册保护的理论和实践。颜色耗尽理论、色差混淆理论、颜色功能理论和不能识别理论等四大反对单一颜色商标注册保护理论的重新审视论证了单一颜色商标的可注册性。单一颜色商标要获得注册保护，需要通过使用获得显著性，并且不能具有实用功能性和美学功能性。在我国，单一颜色商标长期未能获得注册保护，期待借鉴国外有益经验，在《商标法》的下一次修改过程中，将单一颜色纳入可注册商标的范围之内。     

Passport examination by a confocal-type laser profile microscope

The author proposes a nondestructive and highly precise method of measuring the thickness of a film pasted on a passport using a confocal-type laser profile microscope. The effectiveness of this method in passport examination is demonstrated. A confocal-type laser profile microscope is used to create profiles of the film surface and film–paper interface; these profiles are used to calculate the film thickness by employing an algorithm developed by the author. The film thicknesses of the passport samples—35 genuine and 80 counterfeit Japanese passports—are measured nondestructively. The intra-sample standard deviation of the film thicknesses of the genuine and counterfeit Japanese passports was of the order of 1 μm The intersample standard deviations of the film thicknesses of passports forged using the same tools and techniques are expected to be of the order of 1 μm. The thickness values of the films on the machine-readable genuine passports ranged between 31.95 μm and 36.95 μm. The likelihood ratio of this method in the authentication of machine-readable Japanese genuine passports is 11.7. Therefore, this method is effective for the authentification of genuine passports. Since the distribution of the film thickness of all forged passports was considerably larger than the accuracy of this method, this method is considered effective also for revealing the relation among the forged passports and acquiring proof of the crime.     

利用ImageXpress系统灰度特征区分激光打印复印一体机的打印及复印文件初探

目的探索区分激光打印复印一体机的打印文件及复印文件的方法。方法利用ImageXpress系统对理光MP4000BSP激光打印复印一体机的打印文件和复印文件进行灰度特征值的测量。结果两种文件的灰度平均值的平均值和95%置信区间存有明显的差异,且这种差异较为稳定：打印件的平均值约为50,而复印件约为53;打印件的95%置信区间介于50和51.5之间,而复印件的置信区间介于52.5与54之间。结论本方法通过量化对激光打印复印一体机打印及复印文件进行区分是可行的。     

Mythical enjambment in The Hungry Woman: nation,desire, and Cherríe Moraga’s utopic turn

In her play The Hungry Woman: A Mexican Medea (2001), Cherríe Moraga makes use of a technique I call “mythical enjambment”: the insertion of a myth, story, or cultural context into another where it “doesn’t belong,” a willful act of making the unexpected out of the expected. Moraga utilizes mythical enjambment to illuminate how mythologies become entrenched and perpetuate harmful ideologies. Interrupting the traditional aesthetics of Western theater by drawing attention to the ways queer women of color are erased from the narrative, Moraga also challenges the absence of queer women of color from the Chicano movement by embedding her play within some of the most dearly held myths of Chicana/o culture. Ultimately, the use of mythical enjambment gestures toward the utopic and revolutionary potential of theater. The Hungry Woman shatters myths on multiple, intersectional levels: from the critical gaze of interpretive authority to the myths that cohere Chicana/o identity along masculinist and heterosexist lines.     

Identification of group affinity from cross-sectional contours of the human midfacial skeleton using digital morphometrics and 3D laser scanning technology

Identifying group affinity from human crania is a long-standing problem in forensic and physical anthropology. Many craniofacial differences used in forensic skeletal identification are difficult to quantify, although certain measurements of the midfacial skeleton have shown high predictive value for group classifications. This study presents a new method for analyzing midfacial shape variation between different geographic groups. Three-dimensional laser scan models of 90 crania from three populations were used to obtain cross-sectional midfacial contours defined by three standard craniometric landmarks. Elliptic Fourier transforms of the contours were used to extract Fourier coefficients for statistical analysis. After cross-validation, discriminant functions based on the Fourier coefficients provided an average of 86% correct classifications for crania from the three groups. The high rate of accuracy of this method indicates its usefulness for identifying group affinities among human skeletal remains and demonstrates the advantages of digital 3D model-based analysis in forensic research.     

颜色商标及其审查标准研究

颜色商标是指用于指示不同产品和服务提供者、不受固定的外在轮廓限制的单一颜色和颜色组合。颜色商标的形式审查应特别关注申请人是否明确申请将纯粹的颜色注册为商标,以及在以颜色组合申请注册时,是否说明了不同颜色的比例和分布方式。实质审查的重点是显著性审查和功能性审查。