Notes, summaries, assignments, exams, and problems for University

Linux File System Structure: An archive of Linux is associated with 3 parts: superblock, inode table, and data blocks.

Network Ports: To see the ports assigned to services.

Display Active TCP/IP Connections: netstat -a

User Management:

• Create password: passwd (user)
• Add user to group: usermod -g group_name
• Disable: 60001
• Enable: 60002

Practical Commands:

Add User: adduser

1. Change folder privileges: chmod
2. Check privileges: ls -de (see if you changed privileges)

1. Create a user: useradd newuser
passwd newuser
2. Create a directory: The command mkdir is used to create directories:
   mkdir mydirectory
3. Create a report: ps -aux >> reporte.txt
4. Directories associated with the user: -d dirname
5. Changing permission: chmod 744 file.txt /file.txt
6. Change owner: chown
   Entering

To control by PWM requires 2 factors:

1-crossing detection signal by 0.

2-? determine the time, every time you walk by 0.

to detect the zero crossing can be performed
through an operational amplifier connected
comparator.

TCA = 785

Pin Symbol Function

1 GND Earth

2 Q2 *Output 2 Inverted

3 Output U QU

4 Q1 * Output 1 Inverted

5 5Synchronizing voltage Vsync (to detect

zero crossing)

6 Inhibitor

7 QZ Z Output

8 8 Vref voltage stabilized (continuous signal for the

integrator)

9 9 ramp resistor R9 (for the integrator)

10 C10 ramp Capacitance (for the integrator)

11 11 V11 Control Voltage (for comparator)

12 12 C12 pulse Extension

13 LLong pulse

14 Q1 Output 1

15 Q2 Output 2

16 l sSupply voltage.

Verb Tenses

Present Continuous vs. Present Simple

1. I'm angry with William. I am not talking / don't talk to him.

2. Listen! My sister is singing / sings in the shower.

3. This cheese tastes / is tasting strange.

4. Are you thinking / Do you think Ann is pretty?

5. Laura is walking / walks to school every day.

Past Simple vs. Past Continuous

1. The sun SETS (set) in the west.

2. Please don't disturb me. I AM STUDYING (study).

3. I still DON’T KNOW (not know) the answer.

4. DO YOU ALWAYS GO (you / always /go) to the cinema on Friday nights?

5. We HAVE (have) a picnic next Sunday.

Present Simple vs. Present Continuous

6. How much DOES THIS PARCEL WEIGH (this parcel / weigh)?

7. Ms Rivers is busy at the moment. She IS TEACHING (teach).

8. Now I REMEMBER (remember)... Continue reading "Jamie Oliver: A Culinary Icon" »

Inventory Management

Safety Stock: The amount of inventory carried in addition to the expected demand.

Stock Keeping Unit (SKU): A common term used to identify an inventory item.

Material Requirements Planning (MRP)

Available to Promise: A feature of MRP systems that identifies the difference between the number of units currently included in the master schedule and actual (firm) customer orders.

Bill of Materials (BOM): A computer file that contains the complete product description, listing the materials, parts, and components, and the sequence in which the product is created.

Closed-loop MRP: The use of actual data from the production system to continually update the MRP system. This feedback is provided so that planning can be kept valid at all... Continue reading "Key Terms in Production and Inventory Management" »

The Waste Land by T.S. Eliot

1. Sections and Summaries

This poem comprises five sections:

• The Burial of the Dead

  Part I conveys a sense of apprehension and incomprehension among various characters in different situations. Madame Sosostris, a fortune-teller, adds to the confusion with enigmatic pronouncements that only gain clarity later in the poem. The city, particularly London, is depicted as a grim place inhabited by people unable to live fully or escape their deadness.

• A Game of Chess

  Part II presents two scenes showcasing the desolation of people's lives. The first depicts a richly decorated room where a wealthy lady's constant questions reveal her anxiety and lack of control. The second scene unfolds in a London pub, where two women discuss

Preparation of Naphthalene

Naphthalene is a fused-ring aromatic hydrocarbon with two benzene rings. It can be prepared via the following methods:

• From Coal Tar: Coal tar, a by-product of coal processing, is a major source of naphthalene. It is extracted and purified using distillation followed by crystallization.
• Synthesis from Benzene: Benzene undergoes a series of reactions to form naphthalene:
  • Alkylation: Benzene reacts with alkyl halides (like methyl chloride) to form methylbenzene (toluene).
  • Cyclization: Toluene undergoes further reaction with chlorine and heat to form naphthalene.

Preparation of Anthracene

Anthracene is a tricyclic aromatic hydrocarbon consisting of three fused benzene rings. It is mainly obtained from coal tar but can also... Continue reading "Synthesis and Sources of Aromatic Hydrocarbons" »

Insect Defenses Against Predators

Three Plant Mechanisms to Defend Against Insects

• Physical: Thick walls
• Chemical: Phytochemicals that kill insects
• Entrapment: Pitcher plants

How Insects Overcome Physical Defenses

• Specialized mandibles
• Evolution
• Immunity to phytochemicals
• Specialization to survive the digestive liquid of pitcher plants

Insect Parasitism

Endoparasites

Approximately 20% of insect orders include endoparasites. Some orders that include endoparasites are:

• Hymenoptera
• Diptera
• Strepsiptera

Ectoparasites

Some orders that include ectoparasites are:

• Anoplura
• Mallophaga
• Siphonaptera

Three Challenges Faced by Endoparasites

• Respiration
• Excretion/getting rid of toxic nitrogenous waste without killing the host
• Avoiding the host's endocrine system

Insect Social Behavior

Subsocial

#useradd nombredeusuario :: para crear usuarios

#passwd :: nombredelusuario

#groupadd :: nombredelgrupo :: (forma normal)

#groupadd -g 600 nombredelgrupo :: (guid sobre 650)

#userdel nombredelusuario :: para deletear usuarios

#groupdelnombredelgrupo :: borrar el grupo

#usermod -G nombredelgrupo nombredeusuario :: para asignar usuario a grupo.

opcion 2: editar archivo /etc/group -> grupo:x:600:usuarioqueseagregara

#nano /etc/shadow :: para poder ver los usuarios y poder bloquearlos

#passwd -l nombredeusuario :: para bloquear usuario

#passwd -u nombredeusuario :: para desbloquear usuario

#sudo passwd :: para cambiar la contraseña de root

# tail /etc/passwd :: paraver informacion de usuarios

#su nombredelotrousuario :: para iniciar sesion como el usuario... Continue reading "Centos 5.5" »

1. Classifique as variáveis em qualitativa e quantitativa. () Cor preferida. () Índice de liquidez. () Sexo. e) qualitativa, quantitativa, qualitativa .
2. Classifique as variáveis quantitativas em contínuas (c) ou discretas (d).
( ) População: atletas Variável: altura ( ) P.: pacientes de um hospital Variável: pacientes com insuficiência cardíaca. ( ) P.: bebês monitorados em uma UTI neonatal Variável: peso b) contínua, discreta, contínua.
3. Em uma escola de ensino médio, há 300 alunos divididos em 6…..b)36
4. São fases do método estatístico:
1. A apuração. 2. A coleta. 3. A crítica. 4. A definição do problema. 5. O planejamento.
Qual a ordem correta dessas fases? b. 4, 5, 2, 3, 1
5. Considere a série abaixo. Podemos